Croatian Journal of Fisheries Vol 71.1

Editor introductory word The journal has been published since 1938.

During this long publishing history, texts were successively adjusted and modified, following the publishing trends of the time when the magazine was released. Nowadays, Croatian Journal of Fisheries became an international scientific journal that publishes an increasing number of original scientific communications (Fig 1).

Its own website (ribarstvo.agr.hr) contributed greatly to the submission of a large number of papers, especially international ones. It was ob-

served that submissions of full text papers on Croatian language are rare, even by the domestic authors. This suggests that the scientific community changes as they are impelled by the increasingly stringent criteria for scientific promotion.

Finally, it should be noted that competition is big and strong. Therefore, for the future Journal existence and prospects, it is important to be indexed by increasing number of databases and ensure the future progress by continuous improvement of quality level

Fig 1. Number of published papers from 1987 to 2012

Associate professor, Marina Piria, PhD Editor in chief

uvodna rijEč urEdnika Časopis se publicira od 1938. godine. Tijekom povijesti izlaženja, tekstovi su se sukcesivno mijenjali i prilagođavali izdavačkim trendovima vremena u kojem je časopis izlazio. Danas je Croatian Journal of Fisheries postao pravi međunarodni znanstveni časopis gdje se objavljuje sve veći broj originalnih znanstvenih priopćenja (Slika 1).

Vlastita web stranica (ribarstvo.agr.hr) značajno je doprinijela pristizanju velikog broja radova, a po-

sebno stranih radova. Primjećeno je da pristiže mali broj cjelovitih radova na hrvatskom jeziku, čak i od strane domaćih autora. To upućuje da se znanstvena zajednica mijenja na što su ponukani sve strožim kriterijima za napredovanje. Na kraju, potrebno je naglasiti da je konkurencija velika i jaka. Stoga, za budući opstanak časopisa važno je povećati indeksiranost u sve većem broju baza podataka i kontinuiranim poboljšanjem kvalitete osigurati budući probitak.

Slika 1. Broj publiciranih radova od 1987. do 2012.

Prof. dr. sc. Marina Piria Glavna urednica

Croatian Journal of Fisheries, 2013, 71, 1-10 J. D. Wood et al.: Gustatory response in common carp

CODEN RIBAEG ISSN 1330-061X

ORIGINAL SCIENTIFIC PAPER

Gustatory rEsponsE of common carp Cyprinus Carpio to variablE concEntrations of two stimulatory amino acids jonathan david wood*1, paola soledad arce azócar2 Escuela de Postgrado, Facultad de Ciencias Agronómicas, Universidad de Chile, Avenida Santa Rosa 11315, La Pintana, Santiago, Chile, tel.+56 9 77776381; 2 Centro de Innovación Tecnológica, Universidad Técnica Federico Santa María, General Bari 699, Valparaíso, Chile * Corresponding Author, E-mail: jon.wood@ug.uchile.cl 1

ARTICLE INFO

ABSTRACT

Received: 30 September 2012 Received in revised form: 23rd December 2012 Accepted: 28th February 2013 Available online: 29th March 2013

Common carp possesses a highly evolved gustatory system that is stimulated by a narrow range of free amino acids including L-cysteine and L-proline. A synergetic effect on the gustatory response of a combination of these two substances has not previously been demonstrated. In this study, groups of common carp were randomly presented with different concentrations of L-cysteine (0-0.1 M) and L-proline (0-0.05 M) in agar pellets in one minute trials. First retention duration, total retention duration during each trial and the number of ingestions (pellet acceptances) were recorded for each of a total of 690 trials. Palatability, pellet consumption rate and average pellet acceptances were calculated for each pellet type. It was shown that L-cysteine was more highly stimulatory than L-proline but no synergism between the two regarding the gustatory response was observed.

The results are relevant for the formulation of aquafeeds and angling baits for carp.

th

Keywords: common carp, amino acids, Lcysteine, L-proline, gustatory

introduction Common carp Cyprinus carpio has experienced a long history of cultivation on several continents and is one of the species produced in the highest volumes with a total of 2.9 million tonnes cultivated worldwide (FAO, 2009). Additionally, the species is of importance for recreational fishing and a popular target for anglers particularly in Europe and more recently the United States (Rapp et al., 2008) where carp angling has become an economically important activity and a commercially attractive alternative for water bodies (Arlinghaus and Mehner, 2003).

The main objectives of the activities described above are the efficient cultivation and capture of the fish respectively. In order to optimize these, knowledge of the fish biology is of vital importance. Among different aspects of the biology of

carp, the chemosensory system plays a particularly important role because it is connected to the regulation of the feeding behavior of the fish (Pavlov and Kasumyan, 1990). Although feeding behavior is influenced by both exogenous and endogenous factors (Lamb, 2001), an optimum feeding response depends in part on the ability of a fish to locate food, which is often a combination of visual and chemosensory methods (Kasumyan and Døving, 2003).

In both culture and in the wild, carp uses a system of chemoreception composed of olfaction and gustation to optimize the search for food. The structures of major importance in the gustatory response are the taste buds (Sibbing, 1988). Among teleosts, common carp has been shown to possess a particularly highly evolved chemosensory system due to the high number of taste buds present and their location on both the intra- and extraoral sur1

Croatian Journal of Fisheries, 2013, 71, 1-10 J. D. Wood et al.: Gustatory response in common carp

faces of carp (Devitsina, 2006). Due to its preference for waters with high suspended solids and the fact that it feeds both day and night on the bottom of its habitat, it is understandable that the chemoreceptory system should be more highly developed and used as the main way for the fish to find food using chemical signals.

Chemical signals from food are responsible for causing changes in carp movement, increased or decreased appetite and ingestion of greater or lesser quantities of food as a consequence (Atema, 1980), as is the case in other species (Kasumyan et al., 1995; Dias et al., 1997). According to the studies in this area (Kasumyan and Døving, 2003), it has been shown that important differences exist between substances regarding palatability and responses to stimuli among species (Kasumyan and Prokopova, 2001) and geographical location (Kasumyan and Sidorov, 2005). Among the substances studied in fish, the majority of these have included representatives of the four classical taste substances (sweet, salty, sour and bitter) and more recently umami (Roper, 2007).

Other substances include organic acids (Kasumyan and Prokopova, 2001), nucleosides and nucleotides (Carr et al., 1996) and betaine (Barnard, 2006).

However, regarding taste preference and palatability, amino acids have been shown to be particularly stimulatory in carp (Kasumyan and Morsi, 1996).

General findings in fish indicate that only α-amino acids are highly stimulatory, that L-isomers are always more stimulatory than D-isomers and that the stimulatory effectiveness is not directly related to their essentiality (Kasumyan and Døving, 2003). A study by Marui et al., (1983) led to the classification of carp as a fish with a narrow range regarding the number of amino acids that cause positive stimulation. Responses to specific amino acids show no clear relationship with the natural diet of species of fish even though in the natural situation amino acids are important indicators of the presence of food (Carr et al., 1996).

The detection thresholds of fish species to different amino acids are highly variable and so are the intensities of responses to stimulation that have been reported using different methods e.g. olfactometer (Saglio et al., 1990) and impregnated agar pellets (Kasumyan and Morsi, 1996). Several other methods have been utilized for the experimental determination of fish preference to different taste stimuli including electrophysiology (Funakoshi et al., 1981).

Mixtures of amino acids have been shown to have a synergistic or antagonistic effect and combinations of several amino acids have resulted in increased stimulation in other species (Carr, 1976; 2

Takeda, 1984). However, in common carp, with the exception of the study by Saglio et al. (1990) which involved amino acid mixtures to the olfactometer water flow and therefore evaluated olfaction rather than gustation, a gustatory synergistic effect of different concentrations of two highly stimulatory amino acids in food has not been demonstrated.

The incorporation of substances that have been shown to be stimulatory to the chemosensory system of carp is a possible way to increase feed intake and provide benefits for both aquaculturists and anglers. The economic importance of aquaculture is well known. Recreational fishing is a separate, huge industry in itself responsible for anglers spending US$ 42 billion in 2006 alone (U.S.F.W.S. 2006). The formulation of more attractive baits through greater knowledge of amino acid interactions and their relationship with the gustatory system of carp may lead to advances in the formulation of carp aquafeeds and various benefits for anglers, fishery owners, bait manufacture and the environment.

The goal of this study was to demonstrate the gustatory response of common carp to combinations of L-cysteine and L-proline in agar pellets and if possible show the existence of synergic effects of one or more combinations.

matErials and mEtHods a) Fish and tank setup We conducted the experiment on 15 common carp of mean weight 92.1±12.0 g and mean length of 17.3±0.7 cm. The fish were captured using rod and line from Laguna Esmeralda, Región Metropolitana, Chile (S33°38’44”, W71°16’3”). Fish were transferred to the wet lab stock tanks and allowed to acclimatize for a two week period. Fish were maintained on a 12L:12D cycle with lights on at 8.00 a.m.

Following acclimatization, the fish were weighed, measured and transferred to 5 glass aquaria of 70 liters containing dechlorinated tap water in groups of three fish (mean TW 276.2 ± 1.7 grams).

The bottoms of each tank were painted white externally. Filtration was achieved using a 1500 liter/ hour matured biological filter (Atman, China) which provided water movement and oxygenation by way of a venturi. Water quality was monitored during the experiment. Mean dissolved oxygen was 8.9 ± 0.22 mg/L and mean temperature was 20.3 ± 0.78 °C. Total ammonia was kept below 0.22 ± 0.05 mg/L and mean pH was 7.6±0.11. Each aquarium included a hole in the cover glass through which fish could be fed. Fish were fed a carp diet manufactured on-site (44% protein, 29% carbohydrate, 18%

Croatian Journal of Fisheries, 2013, 71, 1-10 J. D. Wood et al.: Gustatory response in common carp

lipid) once per day at a level equivalent to 1% BW. This diet had the following wet weight composition: Soy protein isolate (380 g/kg), cornmeal (250 g/ kg), fish oil (150 g/kg), egg albumin (190 g/kg), vitamin and mineral supplement (30 g/kg).

b) Pellet manufacture and amino acid content Pellets were manufactured from agar powder (Merck Chile, Santiago). To prepare the gel, 100 ml of water was boiled and agar added to it in a proportion of 5%. It was immediately agitated until it was completely dissolved with two drops of Ponceau R4 stain to give the mixture a red color. The correct quantity of pharmagrade L-cysteine and/or L-proline (Merck Chile, Santiago) was weighed using a precision balance and added to the mixture according to the proportions shown in Table 1. The mixture was then poured into a labelled petri dish to a depth of 8 millimeters. The procedure was repeated for the other amino acid combinations. All the mixtures were transferred to the refrigerator and left overnight to enable complete gelling.

After gelling had occurred, a plastic tube of 4 millimeter internal diameter was used to remove cylindrical-shaped agar pellets from each gel. The pellets had a generally soft texture and very slightly rubbery. Care was taken not to crush them when handled. The pellets were transferred to hermetic containers and kept refrigerated at 4 °C between trials. On each fourth day, a new batch of pellets was produced.

Although the trials were based on the experiment used by Kasumyan and Morsi (1996), some changes were made to the experimental design.

Whereas other authors used farmed fish of 12-15 centimeters, we used larger fish because of the size of wild fish available at the time of the experiment.

Carp are not farmed in Chile. The size of the agar pellets used was increased accordingly. Kasumyan and Morsi (1996) used pellets of 2.5 millimeters in length and 1.5 millimeters in diameter. We also used three carp per tank while other authors used individual fish for the trials. This was because common carp are shoal fish (Billard, 1999) and in our

opinion, the presence of conspecifics more closely represented the natural situation.

Additionally, other authors used a control pellet without any amino acids incorporated. This was because they were evaluating both stimulatory and deterrent amino acids. In our case, since L-cysteine and L-proline had both already been established as stimulatory in earlier experiments and L-cysteine had already been found to be more stimulatory than L-proline, our control for comparisons between combinations and determination of synergistic effect was the pellet with the lowest concentration of L-cysteine (pellet %Cys:Pro 0:100).

c) Gustatory response trials Response trials began 15 minutes after the fish had received their daily food ration. One pellet type was randomly selected and a pellet added to the first tank. Several parameters were recorded: 1) the number of times that the pellet was ingested (captured) by the fish during a period of 60 seconds, 2) the length of time that the pellet was kept in the fish’s mouth following initial ingestion, 3) the total duration of the pellet within the mouths of the fish for the 60 second trial, and 4) the consumption rate of pellets, meaning whether the pellet was swallowed or not during the trial. A digital stopwatch (Samsung, Japan) with a lap time function was used to register times and periods. The results of the visual observations were recorded on a spreadsheet.

Following completion of the first trial, we continued with the other tanks in turn, returning to the first tank to carry out the second trial with another pellet type and repeating the sequence until each tank had received one pellet of each of the six types.

The percentage of eaten pellets was determined according to the total number of pellets swallowed compared with the total number presented for each pellet type. We also calculated the index of palatability using the same formula used by Kasumyan and Morsi (1996):

Table 1. Proportions of L-cysteine and L-proline included in each gel. All values are in M as concentrations of the agar gel Stimulant L-cysteine L-proline Total

200:0 0.1000 0 0.1000

100:0 0.0500 0 0.0500

% Cys:Pro 75:25 50:50 0.0375 0.0250 0.0125 0.0250 0.0500 0.0500

25:75 0.0125 0.0375 0.0500

0:100 0 0.0500 0.0500

3

Croatian Journal of Fisheries, 2013, 71, 1-10 J. D. Wood et al.: Gustatory response in common carp

Where Indpal is the index of palatability of the substance (in this case, the combination of amino acids), R is the consumption of pellets with the substance (%), C is the consumption of control pellets (%).

The end of pellet retention in the oral cavity was determined by completion of mastication. For us to record swallowing, the completion of mastication had to occur within the 60 second period. Also, in the event of a pellet not being ingested by a fish during the 60 seconds, the trial was not considered in the consumption calculation. In other words, only pellets that were ingested at least once during the trial were considered in the calculation of consumption rate. Uneaten pellets were removed from the tank at the end of each 60 second trial.

d) Statistical analysis For the statistical analysis of the results we used the Statgraphics Centurion XV v. 15.1.02 (manufactured by StatPoint Inc., USA). The total number of trials was 690 over a period of 23 days.

For the calculation of average number of ingestions, average duration of the first ingestion and average total duration of ingestions in 60 seconds, we carried out two-tailed t-tests at the 95 and 99% confidence intervals between the control values and each of amino acid combinations.

rEsults a) Ingested and non-ingested pellets The general results of the 690 trials are shown in Table 2 indicating the total number of trials carried out and the number of trials that resulted in ingested and non-ingested pellets for each pellet type.

Table 2. General results of the gustatory response trials for the six pellet types used Pellet (% Cys:Pro)

200:0 100:0 75:25 50:50 25:75 0:100 Total number (%)

4

Parameters of taste response Total trials NonNumber of carried out ingested trials with pellets ingested pellets 115 5 110 115 7 108 115 7 108 115 9 106 115 10 105 115 14 101 690 (100) 52 (7.5) 638 (92.5)

Of the total number of 690 trials, 7.5% of trials (52) resulted in the pellets not being ingested at any time during the 60 second periods. The number of non-ingested pellets increased as the concentration of cysteine in the pellet decreased and the concentration of proline in the pellet increased. The highest rate of non-ingested pellets was for the pellet absent of L-cysteine and containing only L-proline, corresponding to 12.2% of the total number of pellets used.

a) Number and duration of ingestions per trial The total numbers of ingestions for all the trials using each pellet type are shown in Table 3. Also shown are the average number of ingestions calculated by dividing the total number of ingestions by the number of trials where ingestion occurred.

For the average number of ingestions, the average duration of the first ingestion and the average total duration of ingestions, values that are significantly different from those of the control are expressed using superscript.

With the exception of pellet type 100:0, both, the total number of ingestions and the average number of ingestions per trial, decreased in a directly proportional manner with increased concentration of L-cysteine and reduced concentration of L-proline in the pellet. The type 100:0 pellet was t-tested and shown not to be significantly different to the 200:0 and 75:25 pellets regarding average number of ingestions per trial. The highest number of ingestions per trial was found to be 12, corresponding to both the 0:100 and 25:75 pellets. The lowest value for the highest number of ingestions per trial was 5 for the 100:0 pellets. All the pellets were found to be significantly different from the control at the 99% confidence level regarding the average number of ingestions per trial.

The highest retention time for the average first ingestion was for that of the 100:0 pellet. The retention times for the three pellet types with the highest concentrations of L-cysteine and lowest concentrations of L-proline (200:0, 100:0 and 75:25) were significantly higher than those of the other pellets. The lowest average first retention was for the pellet with the highest concentration of L-proline (control). In general, the average first retention time decreased with decreasing incorporation of L-cysteine and increasing incorporation of L-proline, although there is a significantly greater difference between the reaction of carp regarding the initial ingestion of the 200:0, 100:0 and 75:25 pellets compared with those of the 50:50, 25:75 and 0:100 pellets.

A similar pattern can be observed with the results of average total duration of pellets in the oral

Croatian Journal of Fisheries, 2013, 71, 1-10 J. D. Wood et al.: Gustatory response in common carp

Table 3. Total and average number of ingestions, average duration of first ingestion and average total duration of ingestions for each pellet type, showing significant differences where appropriate.

Parameters of taste response Average number of Average duration of Average total duration Pellet (% Cys:Pro) Total number of ingestions per trial first ingestion (secs) of ingestions per trial ingestions (secs) 34.70b 47.46b 200:0 191 1.74b b b 100:0 174 1.61 39.11 45.29b b b 75:25 208 1.93 32.65 45.34b b 50:50 246 2.32 24.90 35.92a b 25:75 234 2.23 24.94 37.79b 0:100 (control) 329 3.26 19.52 29.64 Total 1382 a significantly different at 95% confidence level with respect to the control b significantly different at 99% confidence level with respect to the control

cavities during 60 seconds. The duration is shorter for lower L-cysteine and higher L-proline incorporation. All pellets show average total durations that are significantly different from those of the control and four out of five pellets are significantly different at the 99% confidence level. In all three parameters measured, the pellet without L-cysteine indicated the lowest taste preference of carp.

c) Pellet consumption The consumption of pellets followed a similar trend to the previous parameters. Pellet consumption, as a percentage of the total number of pellets ingested, decreased from 82.7% in the case of the 200:0 pellet to 41.6% in the case of the control pellet. However, the relationship between amino acid combination (expressed as L-cysteine concentration) and consumption rate was only partially linear, as can be seen in Figure 1.

d) Palatability Palatability was determined using the formula presented by Kasumyan and Morsi (1996). The results are shown in Table 4.

Table 4. Palatability indices of the pellets compared with the control pellet (0:100) Pellet (% Cys:Pro) 200:0 100:0 75:25 50:50 25:75 0:100

Palatability index (%) +33,1 +28,1 +30,3 +18,4 +22,5 0

Palatability followed the same tendency shown in Figure 1 for consumption rate. The lowest value apart from the control was that of the 50:50 pellet, whereas the highest palatability was that of the 200:0 type pellet which contained the highest concentration of cysteine of all the pellets used.

discussion and conclusions

Figure 1. Relationship between L-cysteine concentration of pellets and consumption rate.

Cysteine and proline have received attention in studies on attraction and taste preference in carp and both have been found to show high stimulatory effectiveness in the species using electrophysiological methods (Marui et al., 1983) and impregnated agar pellets (Kasumyan and Morsi 1996). Invasive electrophysiological methods have also been used on other species (e.g. rainbow trout Oncorhynchus mykiss, Yamashita et al., 2006). Non-invasive methods appear to be more effective than invasive techniques in evaluating stimulatory substances on the chemosensory system with the use of pellets caus5

Croatian Journal of Fisheries, 2013, 71, 1-10 J. D. Wood et al.: Gustatory response in common carp

ing intraoral rather than extraoral responses that can be measured using behavioral techniques. The methods used in this study were effective in showing the gustatory rather than olfactory response to the two free amino acids used and the sensitivity of that response to different concentrations of those substances.

Based on the trials carried out here, it is clear that gustatory system of carp is especially sensitive to amino acids. This has been demonstrated previously with several species of fish including cyprinids (Kasumyan and Døving, 2003). Goh and Tamura (1980) showed that the amino acid spectrum of fish able to cause stimulation is highly species specific. Marui et al. (1983) found that, due to the limited number of amino acids that the authors found to be stimulatory, the taste receptors in carp showed a more narrowly-tuned chemical spectrum than the olfactory system in the same fish. In that study, the authors determined that these were proline, alanine, cysteine, glutamate and glycine. In addition, betaine (trimethylglycine) was considered to be stimulatory. A later study by Saglio et al. (1990) showed the effect of different combinations of amino acids on attraction and exploration by carp. In this study, basic amino acids (histidine, arginine and lysine) and polar, uncharged amino acids (glycine, serine, threonine, tyrosine, asparagine and glutamine) did not cause attraction but did increase exploration by the fish. Acidic amino acids (aspartic and glutamic) did not produce significant activity.

However, non-polar amino acids (alanine, valine, leucine, isoleucine, phenylalanine and methionine) caused significant effects on both attraction and exploration. Also, different pairs (combinations) of acid groups were mixed and tested and the most effective of these were shown to be a combination of non-polar and polar uncharged amino acids with the simplest combination being alanine, valine and glycine.

Proline is a neutral and non-polar amino acid and cysteine is neutral and slightly polar. Although a combination of these two amino acids was used in our study, none of the concentration combinations were more effective than L-cysteine alone.

In the cases of pellets containing both amino acids (75:25, 50:50, 25:75), with a reduced concentration of L-cysteine and increased concentration of L-proline, a lower rate of pellet consumption and lower first and total retention times during the trials were observed.

Other species have been found to be stimulated by a greater number of amino acids. For example, in a review by Kasumyan (1997) the results of oral taste responses of a series of experiments with a to6

tal of 21 fish species indicated that the number of stimulant amino acids ranged from 0 to 13. Even between closely related species, there can be considerable differences in preferences. In the same series of experiments, tench (Tinca tinca), a closely related cyprinid, was found to be stimulated by 12 different amino acids including cysteine and proline and deterred by none, whereas common carp was shown to be stimulated by 6 amino acids (cysteine, proline, glutamic acid, aspartic acid, alanine and glutamine) and deterred by 7. Among the amino acids which most frequently acted as stimulants for these fish are L-alanine, L-cysteine and L-serine. These studies show that amino acids are more often indifferent taste substances than they are stimulatory.

Palatability in common carp has been evaluated for a range of taste substances including amino acids (Hara, 2006). Although dissolved amino acids have been shown to elicit a stimulatory gustatory response via the water in contact with the fish through olfaction (e.g. Saglio et al. 1990), some studies have demonstrated the stimulatory capacity of both cysteine and proline to cause increased consumption of pellets and increased retention time through their action by direct contact with intraoral taste buds (Kasumyan and Morsi 1996) and to cause locomotor activity and searching behavior as well as “pecking” in some cyprinids (e.g. goldfish, Hara 2006). The study by Kasumyan and Morsi (1996) was particularly extensive regarding the number of amino acids tested in common carp and palatability was determined for a total of 21 amino acids plus the classic taste substances. L-cysteine and L-proline (both 0.1 M) were determined to have palatabilities of 74.1% and 55.7%, respectively and consumption rate of pellets of 99.0 ± 1.0% and 51.6% ± 5.2%, respectively. In our case, we compared palatability and consumption rate not with a control absent of amino acids but instead with the pellet with the lowest concentration of L-cysteine and the highest concentration of L-proline, which, we were correct in supposing, would result in the lowest stimulation and act as an effective control. This explains our relatively lower palatability indices. The palatabilities of cysteine:proline mixtures increased as the concentration of L-proline was reduced and that of L-cysteine increased, with the pellet with the highest concentration of L-cysteine (200:0, 0.1M) resulting in the highest consumption rate, palatability and average total retention times per trial and the lowest number of non-ingested pellets. Kasumyan and Morsi (1996) used the same concentration of cysteine and found pellets containing L-cysteine alone to show the highest consumption rate, palatability and first retention duration but not the

Croatian Journal of Fisheries, 2013, 71, 1-10 J. D. Wood et al.: Gustatory response in common carp

longest average total retention time per trial, which was found to be proline in their case. However, Kasumyan and Morsi (1996) found the average number of ingestions (referred to as “catching acts” by the authors) to be 4.9 for proline compared with 1.0 for cysteine. We found something similar with an average number of 3.26 for proline and 1.74 for cysteine (200:0, 0.1M).

Threshold levels have similarly been examined for gustatory system of common carp using electrophysiology (e.g. Marui et al. 1983) and agar pellets (Kasumyan and Morsi 1996) for both L-cysteine and L-proline. Marui et al. (1983) found proline to be the most effective stimulus tested, averaging 10-8.5±0.9 (S.D.) M. Thresholds for other stimulatory substances were in the range of 10-4 – 10-8 M, with that of cysteine to be 10-4.8±0.4 (S.D.) M. These were obtained by adding the test substances to the water flowing through the mouth and out of the gills of paralyzed carp and the stimuli produced by each substance recorded.

Averaged gustatory neural activity was shown to increase with logarithmic increase in stimulus concentration over a wide concentration (6-7 log units).

The authors also indicated a tendency for saturation at concentrations equal to or above 10-3 M. Kasumyan and Morsi (1996) determined threshold concentrations L-cysteine. For cysteine, the concentration at which the consumption of pellets significantly exceeded the level of the control pellet consumption was found to be 0.01 M, or 10-2 M. According to the size of the pellet used in this study, the absolute amount of the substance contained in it was 4.27 μg or 3.53 x 10-10 M. However, they suggested that in reality, the amount is much lower because only the external surface of the pellet comes in touch with the gustatory receptors of the fish and is therefore responsible for acceptance or rejection of the pellet. In our study, the larger size of pellet used meant that the amount of L-cysteine that it contained was 22.8 times higher than the highest concentration used (0.1 M), which meant an absolute amount considering the volume and not only the surface of the pellet of 97.4 μg or 8.05 x 10-9 M. Examples of synergistic gustatory responses have been observed in other species, for example, in pigfish (Orthopristis chrysopterus). A synthetic shrimp extract was manufactured from 19 amino acids and was found to be as stimulatory as a natural shrimp filtrate (Carr, 1976). In European eel (Anguilla anguilla), a mixture of neutral and acidic amino acids and neutral amino acids were shown to be the most palatable combination (Mackie and Mitchell, 1983). Also, synergistic effects were observed when 20 amino acids were mixed with 6 nucleotides and presented to jack mackerel (Ikeda et al., 1988).

Despite the importance of common carp for both aquaculture and recreational angling, little is understood regarding synergistic effects of using more than one amino acid in a feed or bait. According to the results obtained in this study, L-cysteine is clearly more stimulatory than L-proline and decreasing the amount of L-cysteine in a diet or bait would reduce the stimulatory effects of the amino acid. Replacing the concentration of L-cysteine with L-proline reduces rather than enhances the stimulatory response.

The opposite is true if amounts of L-proline were to be replaced by L-cysteine. Here, the preference for L-cysteine over L-proline was demonstrated by the reduced number of ingestions (fewer rejections) of pellets with higher concentrations of L-cysteine and corresponding longer retention times and consumption rate for these combinations.

It has been suggested that the inclusion of free amino acids that are not stimulatory for a species may mask the stimulatory effects of the amino acids or other substances that are (Kasumyan and Døving, 2003). In culture as in the wild, carp uses a system of chemoreception to optimize the search for food and so the taste buds are of major importance (Sibbing, 1988). Carp uses the chemosensory system as its principal way of locating food and making decisions with regard to its handling. Its preference for turbid waters containing high levels of suspended solids and the fact that it feeds both during the day and at night would suggest that carp depends greatly on chemoreception rather than alternative methods of food location such as visual (e.g. bass and trout), electrodetection (e.g. sharks and rays) and mechanoreception (e.g. eels) (Kasumyan and Døving, 2003). It is understandable that the chemosensory systems should be more highly developed and evolved and used as the main way for the fish to find food using chemical signals as previously demonstrated (e.g. Sibbing, 1988). This has been attributed to both the structure (Toyoshima et al., 1984) and distribution and density of taste buds which are present both intra- and extraorally in high densities particularly on the barbels of the fish and on the palatal organ (Devitsina, 2006). The taste buds in these regions are responsible not only for determining the palatability of the food but also its acceptance or rejection, also aiding in the separation of food from non-food before posterior processing occurs (Callan and Sanderson, 2003).

Chemical signals from food items are responsible for changes in carp movement, increased or decreased appetite and greater of lesser amounts of food as a consequence (Atema, 1980). According to studies in this area, it has been shown that important differences exist between substances regarding 7

Croatian Journal of Fisheries, 2013, 71, 1-10 J. D. Wood et al.: Gustatory response in common carp

palatability and responses to stimuli (Kasumyan and Døving, 2003). This is relevant for both carp cultivation and angling. It is in the interest of the feed producer to provoke a positive response in the way of increased food acceptance and consumption as well as higher growth as a result. In the case of bait manufacture, a positive stimulus will result in a higher probability of bait ingestion and subsequent capture of the target fish. For these reasons it is important to know which substances and combinations are the most effective to elicit the most stimulatory response.

The results of studies with taste substances such as amino acids and organic acids (Kasumyan and Prokopova, 2001) have shown high variability between even closely related species. The evidence also suggests that the gustatory response to different substances is genetically specific with low plasticity. This is supported by studies between different geographical locations of fish (e.g. brown trout Salmo trutta, Kasumyan and Sidorov, 2005) and comparative analysis between species living in the same body of water and sharing the same food sources in cyprinids (Giles et al., 1990; Adámek et al., 2003) and salmonids (Ringler, 1985; Bridcut and Giller, 1995).

It is particularly interesting that different fish species display extremely different responses to specific amino acids. In the natural situation, amino acids are important indicators of the presence of food (Carr et al., 1996). However, there seems to be no clear relationship between the amino acid profiles of natural diets of fish species and the responses of those species to specific amino acids. Neither is there a clear relationship between trophic classification (in the case of common carp, omnivore) and the response to different amino acids in the way of active preference or rejection (Kasumyan and Døving, 2003). This would suggest that each species possesses a positive and negative preference for each substance and it is therefore necessary to carry out research with each species and not by family or trophic classification.

Recent research has examined the gustatory response at a higher organizational level (Døving et al., 2009). Greater comprehension of the mechanisms which determine acceptance by fish may lead to increased food consumption, lower feed loss and reduced environmental impact in aquaculture.

The results of this study provide evidence that common carp is able to distinguish between low concentrations of stimulatory amino acids and express preference between combinations of each. No evidence was found that L-cysteine and L-proline act synergistically in the gustatory response produced in the species.

8

It remains to be shown if synergism can be demonstrated using a small number of stimulatory amino acids in the species.

Sažetak okusna rEakcija Šarana Cyprinus Carpio na promjEnjivE koncEntracijE dviju stimulativniH aminokisElina Šaran ima visoko razvijeni okusni sustav kojeg stimulira uski raspon slobodnih aminokiselina uključujući L-cistein i L-prolin. Sinergijski učinak kombinacije ovih dviju tvari na okusnu reakciju nije ranije dokazivan. U ovoj studiji različite koncentracije L-cisteina (0-0,1 M) i L-prolina (0-0,05 M) nasumce su davane testnim skupinama šarana u peletama agara tijekom jednominutnih pokusa. Trajanje prvog zadržavanja i ukupno trajanje zadržavanja tijekom svakog pokusa te broj gutanja (uzimanja) pelete zabilježeni su za svaki od ukupno 690 testova. Za svaki tip pelete izračunata je okusna reakcija, broj konzumacija i prosječno prihvaćanje od strane šarana. Pokazalo se da L-cistein znatno više stimulira konzumaciju od L-prolina te između njih nije uočen sinergizam. Rezultati su važni za pripremanje riblje hrane i ribičkih mamaca za šarane.

Ključne riječi: šaran, aminokiseline, L-cistein, L-prolin, okusni sustav

rEfErEncEs Adámek, Z., Sukop, I., Moreno Rendón, P., Kouril, J. (2003): Food competition between 2+ tench (Tinca tinca L.), common carp (Cyprinus carpio L.) and bigmouth buffalo (Ictiobus cyprinellus Val.) in pond polyculture. J. Appl. Ichthyol., 19, 165-169.

Arlinghaus, R., Mehner, T. (2003): Socio-economic characterization of specialized common carp (Cyprinus carpio L.) anglers in Germany, and implications for inland fisheries management and eutrophication control. Fish. Res. 61, 19-33.

Atema, J. (1980): Chemical senses, chemical signals and feeding behaviour in fishes. pp. 57-101.

In: Fish Behaviour and its Use in the Capture and Culture of Fishes (eds. J.E. Bardach, J.J. Magnuson, R.C. May and J.M. Reinhart).

International Center for Living Aquatic Resources Management, Manila.

Barnard, P. (2006): Gustatory and olfactory feeding responses in Japanese koi carp (Cyprinus carpio). Assignment presented in fulfillment

Croatian Journal of Fisheries, 2013, 71, 1-10 J. D. Wood et al.: Gustatory response in common carp

of the requirements for the degree MPhil in Aquaculture in the Faculty of Agricultural Sciences, Department of Animal Sciences of the University of Stellenbosch, 67pp.

Billard, R. (ed.) (1999): Carp biology and culture.

Springer-Verlag, Berlin. ISBN 1-85233-118-6.

342pp.

Bridcut, E.E., Giller, P.S. (1995): Diet variability and foraging strategies in brown trout (Salmo trutta): an analysis from subpopulations to individuals. Canadian Journal of Fisheries and Aquatic Sciences, 52, 2543–2552.

Callan, T.W., Sanderson, L.S. (2003): Feeding mechanisms in carp: crossflow filtration, palatal protrusions and flow reversals. The Journal of Experimental Biology, 206, 883-892.

Carr, W.E.S. (1976): Chemoreception and feeding behavior in the pigfish, Orthopristis chrysopterus: characterization and identification of stimulatory substances in a shrimp extract. Comparative Biochemistry and Physiology, 55A, 153-157.

Carr, W.E.S., Netherton, J.C., Gleeson, R.A., Derby, C.D. (1996): Stimulants of feeding behavior in fish. Biological Bulletin, 190, 149-160.

Devitsina, G.V. (2006): Adaptive Variability of the Gustatory System Receptor Part of the Carp Cyprinus carpio (Cyprinidae, Teleostei) after Chronic Anosmia. Journal of Evolutionary Biochemistry and Physiology, 42, (6), 743-750.

Dias, J., Gomes, E.F., Kaushik, S.J. (1997): Improvement of feed intake through supplementation with an attractant mix in European seabass fed plant-protein rich diets. Aquatic Living Resources, 10, 385-389.

Døving, K.B, Sandvig, K., Kasumyan, A. (2009): Ligand–specific induction of endocytosis in taste receptor cells. The Journal of Experimental Biology, 212, 42-49.

FAO (2009): FishStat Plus of the Fisheries and Aquaculture Department of the Food and Agriculture Organization of the United Nations, Rome, Italy.

Funakoshi, M., Kawakita, K., Marui, T. (1981): Taste response in the facial nerve of the carp, Cyprinus carpio L. Jpn. J. Physiol. 31, 381-390.

Giles, N., Street, M., Wright, R.M. (1990): Diet composition and prey preference of tench, Tinca tinca (L.), common bream, Abramis brama (L.), perch, Perca fluviatilis L. and roach, Rutilus rutilus (L.), in two contrasting gravel pit lakes: potential trophic overlap with wildfowl. Journal of Fish Biology, 37, 945-957

Goh, Y., Tamura, T. (1980): Effect of amino acids on the feeding behaviour in red sea bream.

Comparative Biochemistry and Physiology, 66C, 225-229.

Hara, T.J. (2006): Feeding behaviour in some teleosts is triggered by single amino acids primarily through olfaction. Journal of Fish Biology, 68, 810-825.

Ikeda, I., Hosokawa, H., Shimeno, S., Takeda, M. (1988): Identification of feeding stimulant in the krill extract for jack mackerel. Bulletin of the Japanese Society of Scientific Fisheries, 54, 235238.

Kasumyan, A.O. (1997): Gustatory reception and feeding behavior in fish. Journal of Ichthyology, 37, 72-86.

Kasumyan, A.O., Døving, K.B. (2003): Taste preferences in fishes. Fish and Fisheries, 4, 289-347.

Kasumyan, A.O., Morsi, A.M.H. (1996): Taste sensitivity of common carp Cyprinus carpio to free amino acids and classical taste substances.

Journal of Ichthyology, 36, 391-403.

Kasumyan, A.O., Prokopova, O.M. (2001): Taste preferences and the dynamics of behavioral taste response in the tench, Tinca tinca (Cyprinidae).

Journal of Ichthyology, 41, 640-653.

Kasumyan, A.O., Sidorov, S.S. (2005): Taste preferences of the brown trout Salmo trutta from three geographically isolated populations. J. Ichthyol.

45, 111-123.

Kasumyan, A.O., Sidorov, S.S., Kazhlaev, A.A., Pashchenko, N.I. (1995): Behavioral responses of young stellate sturgeon to smell and taste of artificial feeds and their components. pp. 278-288.

In: 2nd International Symposium on Sturgeons (eds. A.D. Gershanovich and T.I.J. Smith).

VNIRO Publishing, Moscow.

Lamb, C.F. (2001): Gustation and Feeding Behaviour. pp. 108-124. In: Food Intake in Fish (eds. Houlihan, D., Boujard, T., Jobling, M.) Blackwell Science, Oxford.

Mackie, A.M., Mitchell, A.L. (1983): Studies on the chemical nature of feeding stimulants for the juvenile European eel, Anguilla anguilla (L). Journal of Fish Biology, 22, 425-430.

Marui, T., Harada, S., Kasahara, Y. (1983): Gustatory specificity for amino acids in the facial taste system of the carp, Cyprinus carpio L. J. Comp.

Physiol. 153, 299-308.

Pavlov, D.S., Kasumyan, A.O. (1990): Sensory principles of feeding behavior of fishes, Vopr. Ichtiol., 30, (5), 720-732.

9

Croatian Journal of Fisheries, 2013, 71, 1-10 J. D. Wood et al.: Gustatory response in common carp

Rapp, T., Cooke, S.J., Arlinghaus, R. (2008): Exploitation of specialised fisheries resources: the importance of hook size in recreational angling for large common carp (Cyprinus carpio L.).

Fish. Res. 94, 79–83.

Roper, S.D. (2007): Signal transduction and information processing in mammalian taste buds.

Eur. J. Physiol. 454, 759-776.

Saglio, P., Fauconneau, B., Blanc, J.M. (1990): Orientation of carp, Cyprinus carpio L., to free amino acids from Tubifex extract in an olfactometer. Journal of Fish Biology, 37, 887-898.

Sibbing, F.A. (1988): Specializations and limitations in the utilization of food resources by the carp, Cyprinus carpio: a study of oral food processing.

Environmental Biology of Fishes, 22, 161-178.

Takeda, M., Takii, K. Matsui, K. (1984): Identification of feeding stimulants for juvenile eel. Bulletin of

10

the Japanese Society of Scientific Fisheries, 50, 645-651.

Yamashita, S., Yamada, T., Hara, T.J. (2006): Gustatory responses to feeding- and non-feeding-stimulant chemicals, with an emphasis on amino acids, in rainbow trout. Journal of Fish Biology, 68, 783-800.

Toyoshima, K., Nada O., Shimamura, A. (1984): Fine structure of monoamine-containing basal cells in the taste buds on the barbels of three species of teleosts. Cell Tissue Res. 235, 479484.

U.S.F.W.S. (2006): National Survey of Fishing, Hunting, and Wildlife-Associated Recreation.

U.S. Fish and Wildlife Service, U.S. Department of the Interior, Fish and Wildlife Service, and U.S. Department of Commerce, U.S. Census Bureau. 164pp.

Croatian Journal of Fisheries, 2013, 71, 11-18 K. D. Adeyemi et. al.: Effect of Moringa oleifera marinade on quality attributes of smoked-dried catfish

CODEN RIBAEG ISSN 1330-061X

ORIGINAL SCIENTIFIC PAPER

EffEct of Moringa oleifera marinadE on proximatE composition and sEnsory cHaractEristics of smokEdriEd african catfisH (Clarias gariepinus) kazeem dauda adeyemi1*, aminat mustapha ahmed El-imam2, ayotunde oluwatunbo olorunsanya3, foluke Eunice sola-ojo1, kehinde mathias okukpe1, olusegun oyeshina dosunmu4, rafiat morolayo shittu1, john tolulope idris1 Department of Animal Production, University of Ilorin, Ilorin Nigeria; Department of Microbiology, University of Ilorin, Ilorin Nigeria 3 Department of Animal science, Ibrahim Badamosi Babangida University, Lapai, Nigeria 4 Godbet Homestead Fish Farm, Ilorin, Nigeria * Corresponding Author, E-mail: kazyadeyemi@gmail.com 1 2

ARTICLE INFO

ABSTRACT

Received: 24th October 2012 Received in revised form: 26th December 2012 Accepted: 28th February 2013 Available online: 29th March 2013

The study assessed the effect of Moringa oleifera marinade on chemical composition and organoleptic properties of smokedried catfish in a 6x8 factorial experiment. The experimental treatments are the control, 1, 2 and 3% (w/v) Moringa oleifera Marinade (MOM), 5% brine and 0.2% Butylated Hydroxyl Anisole (BHA) (w/v) solutions. Ninety fishes of average weight of 230±8 g were gutted, washed and randomly assigned to the treatments. Thereafter, the fishes were soaked in the treatments for 2 hours and later hot smoked for 12 hours. After smoking, the fishes were stored in air-free netted boxes and placed on laboratory shelves at room temperature (37±2 °C) for 8 weeks. Samples were taken every seven days for chemical and sensory analysis.

The proximate analysis showed that Moringa oleifera marinade (MOM) reduced the moisture content of smoke-dried fish samples throughout the storage period. The dehydrating property of MOM was concentration dependent with 3% MOM samples having the lowest moisture content, which was significantly different from other treatments. There was no significant difference in the dehydrating properties of 1% MOM, 2% MOM and salt treated samples. All levels of MOM enhanced and maintained the protein, ash and fat content of smoke-dried fish samples.

Sensory scores showed no significant difference among the treatments in terms of color, flavor, juiciness and overall acceptability of fish samples. Moringa oleifera marinade could be used to maintain the quality attributes of smoke-dried African catfish stored for 2 months.

Keywords: Moringa, marinade, smoke-dried fish, brine

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Croatian Journal of Fisheries, 2013, 71, 11-18 K. D. Adeyemi et. al.: Effect of Moringa oleifera marinade on quality attributes of smoked-dried catfish

introduction Fish received increased attention as a potential source of animal protein and essential nutrients for human diets (Ekpenyong and Ibok, 2012). In addition to its nutritional value, fish play important role in providing incomes and poverty alleviation in both rural and urban areas of many developing countries. Due to the susceptibility of fish to chemical, microbial and physical deterioration, various preservation techniques are put in place to check spoilage (Eyo, 1992). Fish spoilage is a metabolic process that causes fish to be undesirable for human consumption due to changes in sensory and nutritional characteristics. Thus, processing and preservation of fresh fish were of utmost importance to maintain product quality, reduce wastage and prevent economic losses (Olley et al., 2000).

Methods of fish preservation include freezing, smoking, canning, sun-drying etc. (Eyo, 1992).

Smoking is the oldest and most common method of fish preservation in many developing countries (Kumolu-Johnson et al., 2010). Smoke-dried fish is a traditional part of the diet of a large section of the world’s population and it is relished for its appetizing flavor and taste (Kiin-Kabiri et al., 2011). In spite of numerous benefits derived from fish smoking, smoke-dried fish is still susceptible to oxidative and microbial spoilage. Traditionally prepared hot smoke-dried fish products suffer heavy insect infestation, high moisture content, bacteria and fungal attack, which cause reduced shelf life (Tobor, 1984).

Hot smoke dried fish is liable to protein degradation due to Millard browning (Gilbert and Knoule, 1975). In addition, smoke deposited on fish during smoking is composed of carboxyl and some poly-nuclear aromatic hydrocarbons, which have been implicated in degenerative diseases such as cancer (Eyo, 2001). In view of the aforementioned problems, it is necessary to enhance the quality attributes and shelf life of smoke-dried fish as well as reduce the hazardous effect of smoke on consumers, hence the use of Moringa oleifera marinade. All parts of Moringa oleifera possess nutritional and medicinal values (Paliwal et al., 2011a). The leaves contain essential amino acids, vitamins and minerals (Fahey, 2005; Grubben and Denton, 2004). Moringa oleifera exhibits potent pharmacological activities, low toxicity and economic viability when compared with synthetic drugs (Paliwal et al., 2011a) and could serve as a functional food (Paliwal et al., 2011b). Myriad phytochemicals present in Moringa are responsible for its pharmacological properties.

An examination of the phytochemicals of moringa species affords the opportunity to examine a range 12

of unique compounds (Fahey et al., 2001; Bennett et al., 2003). Various compounds have been isolated from moringa preparations and are reported to have hypotensive, anticancer and antibacterial properties (Daxenbichler et al., 1991; Bennett et al., 2003; Mekonnen and Dräger, 2003). The objective of this study was to determine the effect of Moringa oleifera marinade on chemical composition and sensory characteristics of smoke-dried African catfish (Clarias gariepinus) stored for two months.

matErials and mEtHods Preparation of Marinade Fresh moringa leaves were obtained from the University of Ilorin, Ilorin, Nigeria. The leaves were air dried for 4 days at ambient temperature (37±2 °C) and ground into powder using a food blender (Starlite, Model No:SL-999 CHINA). Moringa oleifera marinade (MOM) was prepared by adding separately specific quantity (10 g, 20 g or 30 g) of Moringa oleifera leaf powder to 1000 ml of water to form 1, 2 or 3% MOM respectively. 50 g of salt or 2 g of BHA was added separately to 1000 ml of water to form 5% brine or 0.2% BHA solution. No additive was added to the control treatment.

Fish preparation Ninety catfish samples were purchased from Osagbemi Farms in Ilorin metropolis. The processing and smoking of the fishes were carried out at Godbet Homestead Fish Farm, Basin road, Ilorin, Nigeria. The average weight of the fishes was 230±8 g while the total weight was 20 kg. The fishes were gutted using a sharp knife by cutting laterally from the end of the gill cover through the belly portion to the anus. Thereafter, they were thoroughly washed and rinsed. The total weight of the fish after gutting was 18.5 kg with the average weight of 220±6 g. The fishes were randomly assigned to six experimental treatments: Control, 1% MOM, 2% MOM, 3% MOM, 5% salt and 0.2% BHA. Each treatment was replicated thrice with 5 fishes/replicate. The fishes were soaked in the marinade for 2 hours. Thereafter, the fishes were set in the smoking kiln consisting of five-twin tiers and subjected to hot smoking for 12 hours with charcoal as the heat source. The tiers were interchanged every 3 hours to ensure uniform heat distribution and drying. The smoke-dried fishes were placed in air-free netted boxes to prevent flies infestation and stored at room temperature (37±2 °C) for 8 weeks.

Croatian Journal of Fisheries, 2013, 71, 11-18 K. D. Adeyemi et. al.: Effect of Moringa oleifera marinade on quality attributes of smoked-dried catfish

Determination of proximate composition Proximate compositions of samples were determined in accordance to the method of the Association of Official Analytical Chemists (AOAC, 1994). The proximate component determined are moisture content, crude protein, crude fat (ether extract) and ash. Moisture content was measured by weighing the differences before and after drying the fish and this was done at 100-105 °C for 16 h. Protein content (% N x 65) was determined by the Kjeldahl method. Ash content was determined using dry ashing procedures. Fat content was measured by drying the samples at 100 °C in an oven and then extracting the crude fat with petroleum ether in a Soxhlet extractor for 4 hours.

Sensory analysis A sixty-member panel conducted the sensory analysis. The taste panelists (assessors) were drawn from staff and students of the Faculty of Agriculture, University of Ilorin. They were instructed on the parameters to adjudge using a 9-point hedonic scale.

The hedonic scale is delineated as follows: 9=Like extremely, 8=Like very much, 7=Like moderately, 6=Like Slightly, 5=Neither like nor dislike, 4=Dislike slightly, 3=Dislike moderately, 2=Dislike very much, 1=Dislike extremely. Water was provided for the panelists to rinse their mouth after each bite to eliminate the taste of the previous fish sample.

Statistical analysis The experiment followed a 6x8 factorial arrangement in a completely randomized design. The data obtained were analyzed using analysis of the variance (ANOVA) model suitable for the design with the aid of a Genstat discovery program package (fourth edition). The ANOVA model is as follows: Yij= μ+αi+βj+(αi x βj) + eij.

Where Yij denotes the ijth observation arising from level i of additive and level j of storage time μ = overall mean αi = effect of level i of additive βj = effect of level j of storage time (αi x βj) = interaction effect of additive and storage time eij= random error term

rEsults and discussion There were significant differences (P<0.01) in the moisture content of the treatments at various weeks of storage (Table 1). There was a general decrease

in moisture content from the first to eight week of storage. This could be attributed to prevailing ambient temperature and relative humidity around the fish samples. Fish samples treated with 3% Moringa oleifera marinade (MOM) had the lowest moisture content which was significantly different from that of other treatments throughout the storage period.

This was closely followed by 2% MOM, 1% MOM and salt treated samples in that order. There was no significant difference (P>0.01) among fish samples treated with salt, 1% and 2% MOM. The control samples had the highest moisture content, which was followed by BHA treated samples. At the end of the eight week, the moisture content of the control and BHA treated samples exceeded the benchmark of 10% (Daramola et al., 2007) and 12% (Sveinsdottir, 1998) when microbial spoilage might occur. The ability of Moringa oleifera marinade to decrease the moisture content of the fish sample could result from myriad chemical compounds (that have high dehydrating properties) e.g. calcium salts (Grubben and Denton, 2004), present in Moringa oleifera leaves from which the marinade was prepared. Dehydrating properties of salt are well known. Salt decreases the water activity of foods; this mechanism involves transporting salt into food structures and is achieved by various physical and chemical factors such as diffusion, osmosis and a series of complicated chemical and biochemical processes (Turan et al., 2007). Salting is a cheap, popular and effective means of fish preservation (Ayub et al., 2011). A high dehydrating property exhibited

by Moringa oleifera and salt is beneficial in that microbial deterioration is inhibited thus enhancing the shelf life of smoke-dried fish. In addition, both are cheap and readily available. The moisture content of all Moringa oleifera treated samples in the eight week was significantly lower than what was observed in the first week of storage. The moisture content of BHA and control samples followed the same trend. Although, BHA is a potent antioxidant (Adeyemi et al., 2011), it imparted negatively on the moisture content of smoke-dried fish samples.

Moringa oleifera marinade enhanced and stabilized the protein content of smoke-dried fish samples. The crude protein content of all Moringa oleifera samples was significantly higher (P<0.01) than that of other treatments. The increase in the crude protein content of Moringa oleifera samples could be due to the increase in dry matter of processed fish samples as more moisture and volatile compounds are evaporated from the fishes during storage.

Except in week 4 and 6, 3% MOM had the highest crude protein content. The control samples had lowest crude protein values that were significantly 13

Croatian Journal of Fisheries, 2013, 71, 11-18 K. D. Adeyemi et. al.: Effect of Moringa oleifera marinade on quality attributes of smoked-dried catfish

different from other treatments in all storage weeks except in the second and third week of storage when BHA samples had the least. The crude protein content of salt treated samples was higher than control and BHA samples but lower than 1, 2 and 3% MOM samples in the second and third week of storage. The protein content of salt treated samples increased from the first to fifth week and decreased afterwards. A similar trend was observed for the control samples. The results observed for Moringa oleifera samples corroborate the report of Grubben and Denton (2004) that Moringa oleifera leaves contain 9.4 g crude protein/100 g of wet leaves. The extracted and unextracted Moringa leaves gave crude protein values of 43.5 and 25.1% respectively (Makker and Becker, 1997).

There were significant differences in the crude fat content of all treatments in all storage weeks (Table 1). A decrease in the crude fat content of con-

trol, salt and BHA treated samples was observed in the eight week of storage. These values were significantly different from those observed in the first week of storage. All Moringa treated samples maintained the crude fat content of the fish samples from the inception of storage until the eight week.

The crude fat content of the control samples experienced significant fluctuations.

The salt treated samples had the highest ash content which was significantly different (P<0.01) from other treatments throughout the storage period (Table 1). The observation was in line with the report given by AndrĂŠs et al. 2005 who asserted that in addition to product preservation, salt is used to promote nutritional properties and important sensorial changes that make the final product appealing to consumers. Moringa oleifera also increased the ash content of fish samples. However, there were remarkable fluctuations in ash content of the

Table 1: Effect of additives and storage time on proximate composition of smoke-dried catfish Storage time (week) 1 2 3 4 5 6 7 8 Control 20.07zc 13.4za 14.5za 13.97za 15.66zb 21.14zd 16.23yb 14.33ya 7.83xb 8.96xb 7.83yb 12.13yc 5.7wa 10.25xc 5.36va 1%MOM 7.67xb b a b b d a c 6.65x 8.81x 8.13y 12.47y 6.25w 10x 6.82wa 2%MOM 7.86x a a c b c b b 2.62w 5.36w 4.33w 6.77w 3.5v 3.78v 3.01ua 3%MOM 2.48w b a a a b a a 5.66x 6.15w 6.04x 9.73x 6.93x 6.48w 9.25xb 5%Brine 8.44x 0.2%BHA 16.15yc 11.74ya 12.92ya 13.16za 15.54zb 14.64yb 15.04yb 16.45zc * * * * * * * * P2 Control 48.92bx 49.01xb 49.06xb 51.83wc 53.59wd 54.02wd 54.2wd 43va 1%MOM 53.60yb 58.28zd 56.57yc 56.85yc 57.75yd 50.67va 57.18yc 53.87xb 60.1zd 58.71zc 53.39wa 56.02yb 2%MOM 55.26yb 57.99zc 55.79yb 58.38zc b c c a 58.13z 57.43z 55.13x 59.5zd 55.85xa 58.17Zd 60zd 3%MOM 56.37z a b b e f d c 55.52y 59.05z 60z 57.65y 56x 54xa 5%Brine 54.59y 55.54y e b a a d e f 56.66x 59.5z 57.06 y 47.99wb 0.2%BHA 49.52x 45.01w 45.01w 54.79x 2 * * * * * * * * P Control 32.69yd 29.18yb 31.73yc 31.42wc 30.19yc 30.06xc 32.89xd 24.83xa 1%MOM 32.3yc 29.66yb 27.67xa 35.69ze 29.03xa 29.11xa 33.42xd 30.95yb 2%MOM 32.43yb 25.44xa 32.99yb 34.31xc 38.34zd 33.37yc 34.08yc 32.38yb 3%MOM 30.88xc 25.88xa 31.53yc 32.90wd 28.22wb 29.07xb 34.78ye 31.76yc 23.3wa 5%Brine 31.59xe 24.67wa 28.13xd 31.71wf 30.67ye 29.99xe 26.13wc c d d d c c b 31.77y 31.58w 29.81x 29.88x 27.58w 22.22wa 0.2%BHA 30x 31.54y * * * * * * * * P2 Control 18.59xe 20.88vf 17.5xc 11.88va 14xb 13.99wb 12.96xb 16.41vc 1%MOM 19.71yc 21.51wd 19.23yc 13.58xa 14.75xb 14.69wb 12.46xa 22.23ye 2%MOM 17.67wc 23.41xe 16.89wc 12.93wa 14.61xb 14.67wb 12.99xa 19.02wd 14.3xb 14wb 17yd 20xe 3%MOM 17.67wd 22.24xe 15.83vc 12.26wa e e d a c c b 28.68z 25.3z 15.52z 23.49z 23.49y 18.72z 24.71zc 5%Brine 28.67z c f e b d d a 24.37y 19.91y 14.67y 17.68y 17.71x 11.55w 20.2xe 0.2%BHA 16.7v 2 * * * * * * * * P a, b, c, d, e means having different superscript along the same row are significantly different (P<0.01). v, w, x, y, z means having different subscript along the same column are significantly different (P<0.01). * = P<0.01, NS=P>0.01, SED= standard error of difference of means sh (%)

Crude Fat (%)

Crude Protein (%)

Moisture content (%)

Proximate Component

14

Additives

SED

0.39

0.39

0.33

0.25

P2 * * * * * *

* * * * * * * * * * * * * * * * *

Croatian Journal of Fisheries, 2013, 71, 11-18 K. D. Adeyemi et. al.: Effect of Moringa oleifera marinade on quality attributes of smoked-dried catfish

Table 2: Effect of additives and storage time on sensory properties of smoke-dried catfish

Flavour

Tenderness

Colour

Sensory Additives characteristics Control 5%Brine 0.2%BHA 1%MOM 2%MOM 3%MOM P2 Control 5%Brine 0.2%BHA 1%MOM 2%MOM 3%MOM P2 Control 5%Brine 0.2%BHA 1%MOM 2%MOM 3%MOM P2 Control

1 6.4±0.8 7.8±0.9 7.4±0.8 6.0±1.9 6.4±1.9 6.4±1.3 NS 6.4x±0.6 7.4y±0.6 7.2yb±0.5 4.8xa±0.6 6.2x ±0.3 6.8x±0.2 * 6.2a±0.7 7.0a±2.0 7.6b±0.5 5.2a±0.1 6.2±0.7 6.6±1.5 NS

2 8.0±0.6 6.4±0.3 8.0±1.2 7.6±0.5 7.2±0.5 6.8±0.7 NS 7.4±0.9 6.8±0.5 6.8a±.7 6.4a±.4 6.8±.5 6.8±0.4 NS 7.8b±0.8 7.2b±1.2 7.4b±1.2 7.4b±0.9 7.8±0.4 7.2±1.6 NS

3 8.0±0.9 6.4±0.2 7.4±0.2 8.2±0.9 6.0±1.2 7.4±0.1 NS 7±0.3 6.6±0.7 7.2b±0.4 6.4a±0.7 6.8±0.9 7.0±1.2 NS 7.8b0.5 6.0a±0.7 7.6b±0.6 7.0b±0.2 7.0±0.4 7.6±0.5 NS

6.0±0.7

7.6±0.3

7.8±0.5

Storage time (week) 4 5 7.6±0.3 5.6±0.6 4.8±0.6 6.6±0.7 5.4±0.3 6.4±0.8 7.6±0.3 7.6±0.5 6.6±0.8 7.2±0.7 8.0±1.5 6.6±0.4 NS NS 7.6y±0.6 5.4x±0.3 4.6x±0.7 6x±0.1 4.6xa ±.8 6xa±0.4 7.6yb±0.5 7ya±0.7 6x±0.6 6.2x±0.4 8.2y±1.6 7.8y±0.8 * * 7.6yb±0.7 5.0a±0.3 4.8xa±0.9 6a±1.1 5.4xa±0.1 5.4a±0.9 8yb±0.8 7.4b±0.3 6.6x±0.3 6.4±1.1 8y±1.4 7.0±0.4 * NS 7.4y±0.9

5.6±0.5

6 7.4±0.9 5.8±0.2 8.2±0.9 7.6±.2 7.2±1.3 8.2±0.8 NS 7.2±0.2 5.8±0.9 7.6b±0.5 7.0a±0.7 6.6±1.2 8±0.7 NS 6.8a±0.6 5.8a±0.5 8.0c±0.5 7.2b±1.2 7.0±1.0 7.4±1.5 NS 7.4x±0.4

SED 7 8 6.2±0.6 6.8±0.8 6.8±0.4 5.6±0.6 6.8±0.5 3.4±0.4 0.67 7.0±1.5 6.6±0.8 7.0±0.7 6.8±1.3 7.6±0.9 6.2±1.3 NS NS 6.8±0.3 7.0y±1.6 6.8±0.9 5.8x±0.8 6.8a±0.8 4.2xa±0.3 6.6a±0.6 6.4xa±1.1 0.56 6.8±0.7 6.4x±0.3 6.8±0.6 6.8y±0.7 NS * 7.4b±0.2 7.2ya±.7 6.8a±0.3 5.6xa±.1 7.2b±0.6 3.4xa±.5 7.2b±0.4 6.6ya±.4 0.62 7.2±0.5 6.6y±0.6 7.2±0.5 6.8y±0.6 NS * 7.0±0.7

6.8y±0.5

P2 NS NS NS NS NS NS NS NS * * NS NS * * * * NS NS

NS NS * * NS NS

Overall acceptability

Juiciness

5%Brine 6.4±0.3 7.2±0.7 6.0±0.8 5.0x±0.7 5.8±.6 5.6x±0.1 7.6±0.6 5.4x±0.5 8yb±1.2 7.2±0.9 3.6xa±.3 0.84 0.2%BHA 6.8a±0.4 8.0b±0.5 7.4b±0.1 5.4xa±.6 5.4a±0.9 a b b a b 6.8xa±1 7.2b±0.6 6.2ya±.4 1%MOM 5.0 ±1.0 7.8 ±0.6 7.6 ±0.5 7.8y ±.6 6.8 ±0.7 7.6±1 6.4y±.4 2%MOM 6.4±0.7 7.2±0.5 7.4±1.3 6.4x±1.4 6.8±0.3 6.8x±0.6 7.4±1 6.8y±1.9 3%MOM 6.8±0.7 7.0±0.6 7.2±0.7 8.2y±1.4 7.6±0.4 7.6x±1.2 NS NS NS * NS * NS * P2 Control 7.0a±1.4 8.2b±0.4 7.8b±0.7 7.8yb±0.8 5.2a±0.3 7.2a±0.2 7.0a±1.3 7.0ya±0.6 * * 5%Brine 7.0a±0.9 7.4b±0.8 6.4a±0.6 4.8xa±0.8 6.2a±0.6 6.0a±0.1 7.2b±0.5 6.2ya±0.7 * 0.2%BHA 7.4b±0.9 7.8b±0.7 7.8b±0.7 5.2xa±0.6 5.6a±0.5 7.6b±0.5 7.0b±1.0 3.6xa±0.7 8b±1.4 7.4b±0.3 7.8yb±0.7 7.2b±1.3 6.8a±0.6 6.8a±0.9 6.2ya±1.0 0.85 * 1%MOM 4.6a±1.5 NS 2%MOM 6.4±1.3 7.8±1.2 7.4±0.4 6.2x±1.1 6.4±1.6 6.4±0.4 7.2±0.5 6.6y±1.2 NS 3%MOM 6.4±0.9 7.6±1.0 7.0±1.1 8y±1.4 7.4±1.0 8.2±1.5 7.0±0.8 7.0y±1.6 NS NS NS * NS NS NS * P2 Values are mean ± SD. a, b, c means having different superscript along the same row are significantly different (P<0.01). x, y, z means having different subscript along the same column are significantly different (P<0.05). *=P<0.01, NS=P>0.01, SED=Standard error of difference of means. SD=standard deviation

fish samples throughout the storage period. It has been reported that Moringa oleifera leaves contained substantial macro and micro minerals (Booth and Wickens, 1988).

There was no significant difference (P>0.01) among the treatments with respect to color perceived by assessors (Table 2). All treatments were rated as having the same color throughout the storage period. A visual appraisal of the fishes showed that all samples had dark color. This dark color was probably due to smoke and ashes deposited on the

fishes during smoke-drying process. Moringa oleifera treated samples had dark greenish patches on them. The intensity of the greenish patches was concentration dependent with 1% MOM having the least.

Flavor score for the control samples increased from the first to fourth week, decreased from the fifth to sixth week and increased afterwards (Table 2). There was a decrease in the scores assigned to salt and BHA treated samples. The flavor scores observed in the eight week for salt and BHA sam15

Croatian Journal of Fisheries, 2013, 71, 11-18 K. D. Adeyemi et. al.: Effect of Moringa oleifera marinade on quality attributes of smoked-dried catfish

ples were lower and differed significantly from those observed in the first week of storage. There were fluctuations in the flavor scores observed for all treatments. Except in the fourth and eight week of storage, there were no significant differences in flavor among the treatments throughout the storage period. The scores for all Moringa treated samples in the eight week do not differ from that of the first week.

For tenderness, with the exception of BHA and 1% MOM, there was no significant difference (P>0.01) among the scores assigned to the treatments from the first to eight week of storage. There was a decrease in the scores for BHA samples. The scores for 1% MOM differ slightly throughout the storage weeks. In the first week of storage, 2% MOM had the highest score which was significantly different from other treatments. No significant difference (P>0.01) was observed in the second, third, sixth and seventh week among the treatments. In the fourth week, the control and 1% MOM had significantly higher scores than other treatments. 3% MOM had the highest score in the fifth week. The control and 3% MOM were rated higher than other treatments in the eight week. No significant difference was observed in the juiciness of all treatments except BHA and 0.1% MOM as storage progressed.

The overall acceptability among the treatments did not differ (P>0.01) except in the fourth and eight week. There was no significant difference among Moringa treated samples and the control in the fourth and eight week. BHA samples had the least scores in these weeks.

The reduction in sensory scores as storage progressed could be attributed to the activity of spoilage agents. Quality loss during storage at both ambient temperature and chilling was revealed in the results of research on storage of Oyster (Llobreda et al., 1986) and Shrimps (Reilly and Dela-cruz, 1986).

Although chemical quality indices of smoked-dried fish could predict their biological utilization by consumers (Trinidad and Estrada, 1986), physical assessment method is easily available to an intending fish buyer. While physical or subjective methods of analysis may suffer from the limitation of being subject to bias by the assessor and hence may not be reproducible, the chemical methods are reliable measures of freshness or state of deterioration of a product (Daramola et al., 2007). This major limitation of subjective method is evident in this study where assessors ranked 3% MOM with a moisture content of 2.48% and control with a moisture content of 20% in the first week as having the same tenderness.

16

conclusion All levels of Moringa oleifera marinade reduced the moisture content of smoke-dried African catfish.

The dehydrating property of Moringa oleifera depends on concentration. 3% MOM samples had the least moisture content which was significantly different (P<0.01) from other additives. There was no significant difference (P>0.01) in the moisture content of samples treated with salt, 1% and 2% MOM. Control samples had the highest moisture content, which was closely followed by BHA samples. Moringa oleifera marinade improved and stabilized the crude protein and fat content of the fishes throughout the storage period. In this respect, 3% MOM was the most effective. Salt treated samples had the highest ash content throughout the storage period. This was significantly different from other additives. There was no significant difference in the ash content of Moringa oleifera treatments. There was no significant difference in the organoleptic properties of the additives during most of the storage period. Moringa oleifera marinade could be used to improve the chemical composition and shelf life of smoke-dried African catfish. Further studies should be carried out to determine the effect of mixing Moringa oleifera with salt on the chemical composition and sensory characteristics of smoke-dried African catfish for a longer period of storage.

Sažetak učinak marinadE Moringa oleifera na nEposrEdan sastav i sEnZorna svojstva dimljEnoG afričkoG soma (Clarias gariepinus) Ovim istraživanjem izmjeren je učinak marinade Moringa oleifera na kemijski sastav i organoleptička svojstva dimljenog soma pomoću faktorskg eksperimenta 6x8. Eksperimentalna obrada uključivala je kontrolu, marinadu Moringa oleifera (MOM) od 1, 2 i 3% (w/v), otopine rasola od 5% i butil-hidroksilanisola (BHA) od 0,2% (w/v). Izvađena je utroba devedeset riba prosječne težine 230±8 g, oprane su te im je nasumce određena vrsta tretmana. Nakon toga ribe su se dva sata namakale u otopinama te potom bile dimljene dvanaest sati. Nakon dimljenja, ribe su spremane u vakuumske mrežaste kutije te su ostavljene na policama laboratorija na sobnoj temperaturi (37±2 °C) tijekom 8 tjedana. Uzimani su uzorci svakih sedam dana za kemijsku i senzornu analizu. Neposredna analiza je pokazala da je marinada Moringa oleifera (MOM) smanjila udio vlažnosti kod dimljenih uzoraka ribe tijekom skladištenja.

Croatian Journal of Fisheries, 2013, 71, 11-18 K. D. Adeyemi et. al.: Effect of Moringa oleifera marinade on quality attributes of smoked-dried catfish

Dehidrirajuće svojstvo MOM-a je ovisilo o koncentraciji te su uzorci tretiranih s MOM-om od 3% imali najniži udio vlažnosti, što se znatno razlikovalo od drugih načina obrade. Nije bilo značajnije razlike u dehidrirajućim svojstvima MOM-a od 1% i 2% te uzoraka koji su tretirani solju. Sve razine MOM-a su poboljšale i održale udio proteina, pepela i masti kod uzoraka dimljene ribe. Senzorne ocjene nisu pokazale značajne razlike među načinima obrade u smislu boje, okusa, sočnosti i ukupne prihvatljivosti uzoraka ribe. Marinada Moringa oleifera se može koristiti za očuvanje kvalitete dimljenog afričkog soma koji se skladišti dva mjeseca.

Ključne riječi: Moringa, marinada, dimljena riba, rasol

rEfErEncEs Adeyemi, K.D., Olorunsanya, A.O., Akanji, M.A. (2011): Effect of watermelon (Citrulus lantus) extracts on oxidative stability of broiler meat.

African Journal of General Agriculture, 7, (3), 103-108.

Andrés, A., Rodríguez-Barona, S., Barat, J. M., Fito, P. (2005): Salted cod manufacturing: Influence of salting procedure on process yield and product characteristics. Journal of Food Engineering, 69, 467-471.

AOAC (Association of Official Analytical Chemists) (1994): Official Methods of Analysis of the Association of Official Analytical Chemists, Vols.

I and II, Association of Analytical Chemists, Arlington, 1298 pp.

Ayub, V. O, Jackson, H. O., Samuel, W., Douglas, A., Gabriel, O. D., John, G. (2011): Comparison of Different Techniques for Processing and Preserving fish Rastrineobola argentea from Lake Victoria, Kenya. World. Academy of Science, Engineering and Technology, 60, 1643-1647.

Bennett, R.N., Mellon, F.A., Foidl, N., Pratt, J.H., DuPont, M.S., Perkins, L., Kroon, P.A. (2003): Profiling glucosinolates and phenolics in vegetative and reproductive tissues of the multi-purpose trees Moringa oleifera L. (Horseradish tree) and Moringa stenopetala L. Journal of Agricultural and Food Chemistry, 51, 3546-3553.

Booth, F.E.M., Wickens, G.E. (1988): Non-timber uses of selected arid zone trees and shrubs in Africa. FAO conservation guide, Rome, pp 92101.

Daramola, J.A., Fasakin, E.A., Adeparusi, E.O (2007): Changes in physiochemical and sensory

characteristic of smoke-dried fish species stored at ambient temperature. African Journal of Food, Agriculture, Nutrition and Development, 7, (6), 1-16.

Daxenbichler, M.E., Spencer, G.F., Calson, D.G., Rose, G.B., Brinker, A.M and Powell, R.G. (1991): Glucosinolate composition of seeds from 297 species of wild plants. Phytochemistry, 30, 26232638.

Ekpenyong, C.O., Ibok, C.O. (2012): Effect of smoking, salting and frozen storage on the nutrient composition of the African catfish (Clarias gariepinus). Journal of Food, Agriculture and Environment, 10, (1), 12-16.

Eyo, A.A. (1992): The nutritive value of traditionally prepared fish meals. FAO fisheries report.

No. 467, sup 147-149.

Eyo, A.A. (1999): Storage potential and utilization of tilapia mince, Proceedings, 13th Annual Conference of Fishery Soceity of Nigeria, pp: 135-145.

Eyo, A.A. (2001): Fish processing Technology in the Tropics. National Institute for Freshwater Fisheries Research, New Bussa, Nigeria. ISBN13: 9781770857, pp 403.

Fahey, J.W. (2005): Moringa oleifera: A review of the medical evidence for its nutritional, therapeutic and prophylactic properties. Part 1, Trees Life Journal, 1, 5.

Fahey, J.W. Zakmann, A.T., Talalay, P. (2001): The chemical diversity and distribution of glucosinolates and isothiocyanates among plants.

Corrigendum: Phytochemistry, (59), 200- 237.

Gilbert, J., Knoule, M.E. (1975): The chemistry of smoked foods, A review. Journal of Food Technology, 10, 245- 261.

Grubben, G.J.H., Denton, O.A. (2004): Plant Resources of Tropical Africa 2. Vegetables.

PROTA Foundation, Wageningen, Netherlands/ Backhuys Publishers, Leiden, Netherlands/ CTA, Wageningen, Netherlands.

Kiin-Kabari, D.B, Barimalaa, I.S., Achinewhu S.C, Adeniji, T.A. (2011): Effects of Extracts From three indigenous spices on the chemical stability of smoke-dried catfish (Clarias Lezera) During Storage. African Journal of Food, Agriculture, Nutrition and Development, 11, (6), 5335-5343.

Kumolu-Johnson, N.F. Aladetohun, C.A., Ndimele A. (2010): The effect of smoking on the nutrient composition of the African catfish (Clarias gariepinus). African Journal of Biotechnology, 9, 7376.

17

Croatian Journal of Fisheries, 2013, 71, 11-18 K. D. Adeyemi et. al.: Effect of Moringa oleifera marinade on quality attributes of smoked-dried catfish

Llobreda A.T., Bukalacao M.L. and Sunaz, N. (1986): Effects of storage on the microbial quality of slipper oyster. Cassostera iredalei. In: J. L Maclean, L. B. D Izon and L.V Hosilus (Eds). The First Asian Fisheries Forum, Manilla, Philippines, 437-442.

Makkar, H.P.S., Becker, K (1997): Nutrients and antiquality factors in different morphological parts of the Moringa oleifera tree. Journal of Agricultural Science, 128, 311-322.

Mekonnen, Y., Dräger, B. (2003): Glucosinolates in Moringa stenopetala. Planta medica, 69, 380-382.

Olley, J., Doe, P.E., Heruwaty E.S. (1988): The influence of drying and smoking on the nutritional properties of Fish. An introductory overview. In: Fish Smoking and Drying, Burt, J.R. (Ed.). Elsevier Applied Science, London, ISBN: 1-85166-247-2, pp: 1-22.

Paliwal, R., Sharma, V., Pracheta (2011a): A Review on Horse Radish Tree (Moringa oleifera): A Multipurpose Tree with High Economic and Commercial Importance. Asian J. Biotechnology, 3, 317-328.

Paliwal, R., Sharma V, Pracheta, Sharma, S. (2011b): Elucidation of free radical scavenging and antioxidant activity of aqueous and hydro-ethanolic extracts of Moringa oleifera pods. Res. J. Pharm.

Tech, 4, 566-571.

18

Reilly A.E., Dela-cruz, D (1986): Post-harvest Spoilage of Shrimp (Penaeus monodon). In: Maclean JL, Dixon LB and Hossillus LV (Eds).

The First Asian Fisheries Forum. Manilla, Philippine, 455-458.

Sveinsdottir, K. (1998): The process of fish smoking and quality evaluation. M.Sc Dissertation, University of Denmark, pp 24 Tobor, T.G. (1984): A review of fish industry and status of fish preservation methods and future growth prerequisites to cope with anticipated increase in production. NIOMR Tech.paper, No.17.

Trinidad, L.M., Estrada, M.H. (1986): Effect of raw material freshness on the quality of smoked Tilapia (Oreochromis niloticus). In: Maclean JL, Dixon L B and Hosilus LV(Eds). The first Asian Fisheries forum. Manilla, Philippines, 471-472.

Turan, H., Sönmez, G., Çelik, M. Y., Yalçin, M. (2007): Effects of different salting process on the storage quality of Mediterranean Muscle (Mytilus Galloprovincialis L. 1819). Journal of Muscle Foods, 18, 380-390.

Croatian Journal of Fisheries, 2013, 71, 19-24 I. T. Omoniyi et. al.: Toxicity of Dichlorvos on Clarias gariepinus

CODEN RIBAEG ISSN 1330-061X

ORIGINAL SCIENTIFIC PAPER

lEtHal EffEcts of 2,2-dicHlorovinyl dimEtHyl pHospHatE (ddvp) on finGErlinG and juvEnilE Clarias gariepinus (burcHEll, 1822) isac tunde omoniyi*, kazeem lanre adeogun, samuel olubodun obasa Department of Aquaculture and Fisheries Management, Federal University of Agriculture, Abeokuta, Nigeria tel. +2348038093831 * Corresponding Author, E-mail: itomoniyi@yahoo.com

ARTICLE INFO

ABSTRACT

Received: 28th April 2012 Received in revised form: 15th January 2013 Accepted: 28th February 2013 Available online: 29th March 2013

This study investigated the lethal toxicity of 2,2-dichlorovinyl dimethyl phosphate (DDVP) on African mud catfish, Clarias gariepinus fingerlings (mean weight 7.02 ± 2.56 g) and juveniles (mean weight 13.54 ± 1.46 g) in a static renewable bioassay.

DDVP, also known as Dichlorvos is an organophosphate pesticide. Each treatment in the lethal test was in triplicates with bioassay media concentrations (fingerlings: 0, 250, 275, 300, 325 μgL-1) and (juveniles: 0, 400, 450, 500, 600 μgL-1). Data on fish mortality as well as the physico-chemical parameters (temperature, pH, dissolved oxygen and electrical conductivity, EC) of water were collected and subsequently subjected to a one way analysis of variance (ANOVA) at 5% probability level. Duncan Multiple Range Test (DMRT) was used to separate differences between means. The median lethal concentration (LC50) and median lethal time (LT50) were determined by probit analysis. The water quality parameters of the treatment tanks showed no significant difference with those of the control except for conductivity and pH. Behavioural responses in the fishes included erratic and uncoordinated swimming which were observed to be more pronounced in the juveniles. Bleached body was the only external change observed and this was more pronounced in the fingerlings. The 96-hr LC50 for fingerlings and juveniles were 275.2 and 492.0 μgL-1 respectively. The LT50 values for fingerlings were 48.10 and 7.77 hrs for concentrations 250 and 325 μgL-1 respectively; while those of juveniles were 25.54 and 5.34 hrs for 400 and 600 μgL-1 respectively. The results indicated that DDVP was 1.79 times more toxic to the fingerlings than the juveniles.

Keywords: Dichlorvos, Toxicity, Clarias gariepinus, LC50 , LT50

introduction Fish is the cheapest animal protein source in Nigeria because of its availability, palatability and health provision (Fawole et. al., 2007). Agbon et. al.

(2010) also remarked that fish is a heavily traded food commodity in the country and it is becoming a fastest growing agricultural item in international

markets. However, fish populations in water bodies are susceptible to environmental impacts caused by the introduction of exotic species, industrial wastes, oil spills, pesticides and other agents that directly affect the ecology and the survival of species.

Pesticides contain poisonous substances (toxicants) that distort water quality and impose physiological stress on biotic community of the water body which 19

Croatian Journal of Fisheries, 2013, 71, 19-24 I. T. Omoniyi et. al.: Toxicity of Dichlorvos on Clarias gariepinus

is the home of fish (Asonye et. al., 2007).

In Nigeria, agrochemicals that contain such pesticides, especially chlorinated hydrocarbons and the organophosphates, are routinely employed as part of the integrated farming practice to protect crops and animals from insects, weeds and diseases (Fafioye et. al., 2001). Thus, toxicity tests become imperative to estimate potential hazards as part of risk assessment protocols in agriculture, especially in fish farming. Toxicity tests are performed for the specific purpose of predicting what biological functions would be perturbed by the toxicant exposure or explicitly quantify the effect of a toxicant on the health of an organism (Omoniyi et. al., 2002; Omoregie et. al., 2009). A number of factors influence the response of organisms to toxicity tests. These factors include age, disease, water quality, stage in life history/cycle, pollutant interaction, nutrient status, reproductive stage and species interactions. Different species of organisms vary in their vulnerability to specific pollutant (Umar et. al., 2010). Joshi et. al.

(2002) reported that the most adverse effect of organophosphate pesticides (Chloropyrifos) on Tilapia guineensis were observed in fish exposed to 0.1 mgL1 . Omitoyin et. al. (2006) reported that LT50 was 26 and 67 hrs in 1.8 mgL-1 and 0.8 mgL-1 for Clarias gariepinus when exposed to Lindane. Idi-Ogede et. al. (2012) reported the 96-hr LC50 value of 8.20 mgL-1 on exposure of C. gariepinus to Sniper 1000EC (an organophosphate pesticide). Fish is a non-target organism to the use of agricultural chemicals but it is affected through loss of habitat and food supply.

Dichlorvos also known as DDVP (2,2-dichloro-vinyl dimethyl phosphate) is imported, marketed and used by farmers in Nigeria (Fawole et. al., 2007).

Therefore, this study was conducted to investigate the lethal toxicity of Dichlorvos on a commercially important farmed fish species as C. gariepinus under laboratory conditions. The study is necessary to secure additional knowledge on the toxicology and the use of the pesticide by agriculturists, especially fish farmers in the country.

matErials and mEtHods The pesticide used is a Dichlorvos with a chemical formula of 2,2-dichlorovinyl dimethyl phosphate, C4H7Cl2O4P (DDVP). It is a contact acting and fumigant pesticide for the control of a wide range of insects. It is an emulsifiable concentrate (EC) containing 1000 mgL-1 DDVP. It was purchased from a reputable agrochemical stores in Abeokuta, Ogun State, Nigeria.

Both the fingerlings and juveniles of C. gariepinus were procured in batches from a reputable 20

commercial fish farm in Abeokuta. The fish were transported in polythene bags half filled with five litres of dechlorinated tap water (from storage tank) to the laboratory where they were held in a large water bath of 160 L capacity for acclimation over 14 days. The fish were not fed in the first two days of acclimation after which they were fed 3% body weight with Coppens fish feed containing 45% crude protein as described by Omoniyi et. al. (2002).

The water in the bath was replenished with dechlorinated municipal tap water and uneaten food and faecal matter were siphoned out. A total mortality of 2% was recorded during the acclimation. Feeding of fish was stopped 24 hours before commencement of the experiment.

Four concentrations (250, 275, 300, 325 μgL-1) of the bioassay media were prepared and a control (0 μgL-1) was maintained. The volume of each test solution in fifteen 60×30×20 cm glass aquaria was 20 litres for all treatments in triplicates. Ten acclimated fingerlings (mean weight 7.02±2.56 g; total length 6.2±1.4 cm) were randomly introduced into each aquarium for the acute bioassay test starting from the control. The fish were not fed during the 96-hour duration of the acute toxicity experiment as described by Omoniyi et. al. (2002) and Omoregie et. al. (2009). Similar procedures were used for the juveniles (mean weight 13.54±1.46g; total length 14.4±2.0 cm) with different concentrations of 400, 450, 500, 600 μgL-1 solutions and a control maintained.

The physical and chemical parameters of the media including water temperature, hydrogen ion concentration (pH), dissolved oxygen (DO) and water conductivity were monitored and recorded. The behavioural responses of the test fish to the toxicant at different concentrations were observed and recorded. Fish were confirmed dead when they did not react to touch stimulus. The fish were also observed for any external changes in the body while in the test media.

Data from physico-chemical parameters of the test media were subjected to one way analysis of variance (ANOVA) at 5% probability level. Duncan Multiple Range Test (DMRT) was used to determine the difference between means of treatment when ANOVA showed significance. The median lethal toxicity (LC50) and median lethal time (LT50) were determined using probit analysis as described

by Wardlaw (1985).

rEsults The temperature and dissolved oxygen content (DO) of the test water fluctuated slightly during the toxicity test as shown in Table 1. During the toxicity

Croatian Journal of Fisheries, 2013, 71, 19-24 I. T. Omoniyi et. al.: Toxicity of Dichlorvos on Clarias gariepinus

Table 1. Mean values of physico-chemical parameters of different concentrations during acute toxicity Concentration (μgL-1)

DO (mgL-1)

Temperature (°C)

pH

26.38 ±0.05a 6.59 ±0.03a 0 6.24 ±0.04a a a 250 6.14 ±0.24 26.68 ±0.25 6.49 ±0.33a a b 275 6.18 ±0.02 26.77 ±0.23 6.34 ±0.02b a b 300 6.16 ±0.12 26.76 ±0.12 6.16 ±0.05c 325 6.13 ±0.04a 26.76 ±0.05b 6.09 ±0.02d Values with the same alphabets along the column were not significantly (p>0.05) different

test, DO ranged between 6.13 and 6.24 mgL-1, pH from 6.09 to 6.59; temperature from 26.38 to 26.770C and conductivity from 146.27 to 170.39 μScm-1. The water quality parameters of the treatment tanks varied significantly (p<0.05) with those of the control except for DO. DDVP induced severe behavioural responses in the two stages of the fish. Behavioural responses observed were lateral and upward bending of the body, erratic and spiral swimming, spontaneous air gulping at different rates, sudden quick movement/jumping, respiratory distress and state of calmness.

Bleached body with lesions was the only external change observed in the test fish and this was more in the fingerlings at higher concentrations.

All the fish in the control medium survived during the toxicity experiment, while mortalities were observed in all treatments as shown in Tables 2 and 3.

Table 2. Mortality in the three replicates of Clarias gariepinus fingerlings in different concentrations of DDVP at 96-hr period Concentration (μgL-1 ) 0 250 275 300 325

1 0 2 7 7 9

Replicates 2 0 0 5 8 10

3 0 2 6 9 10

Mortality (%)

Conductivity (uScm-1`) 146.27 ±0.08a 150.52 ±0.02b 160.28 ±0.24c 168.22 ±0.28d 170.39 ±0.12e

With respect to mortality, all treatments varied significantly (p<0.05) from the control. Mucus was copiously observed on the gills of the dead fish in all treatments except the control which recorded no mortality. The probit mortality curves are shown in Figures 1 and 2 for the fingerlings and juveniles respectively. The curves were subjected to regression analysis and the 96-hr LC50 of DDVP were estimated to be 275.2 μgL-1 and 429.0 μgL-1 for the fingerling and juvenile respectively.

Fig 1. Linear relationship between logarithm of concentration and percentage mortality of Clarias gariepinus fingerling exposed to different acute concentrations of DDVP

0.00 13.33 60.00 80.00 96.67

Table 3. Mortality in the three replicates of Clarias gariepinus juvenile in different concentrations of DDVP at 96-hr period Concentration (μgL-1 ) 0 400 450 500 600

1 0 1 3 4 9

Replicates 2 0 1 3 7 10

3 0 3 4 10 9

Mortality (%) 0.00 20.00 33.33 70.00 93.33

Fig 2. Linear relationship between logarithm of concentration and percentage mortality of Clarias gariepinus juvenile exposed to different acute concentrations of DDVP 21

Croatian Journal of Fisheries, 2013, 71, 19-24 I. T. Omoniyi et. al.: Toxicity of Dichlorvos on Clarias gariepinus

The linear relationship of 96-hr LT50- probity mortality was estimated to be 48.10 and 7.77 hrs for concentrations 250 and 325 ÎźL-1 in fingerlings, while the juvenile fish were 25.94 and 5.34 hrs for concentrations at 400 and 600 ÎźgL-1 respectively. These time-probity mortality curves are shown in Figures 3 and 4 for fingerlings and juveniles respectively.

The calculated toxicity severity of the pesticide on the two developmental stages of C. gariepinus revealed that DDVP was 1.79 times more toxic to the fingerlings than the juvenile stage.

Fig 4. Linear relationship between logarithm of time and probit mortality of juvenile exposed to different acute concentrations of DDVP

Fig 3. Linear relationship between logarithm of time and probit mortality in different concentration of Clarias gariepinus fingerling exposed to acute concentrations of DDVP

discussion The lethal toxicity test showed that all the fish in the control medium survived while mortalities were observed in all treatments. The mortality increased with increasing concentration of the toxicant in water showed a dose-response relation which has been reported by many authors including Agbon et. al. (2002), Omoregie et. al. (2009) and Umar et. al. (2010). Mucus observed on the gills of the dead fish might be responsible for the mortality recorded in this study. Omoniyi et. al. (2002) reported that accumulation of mucus on gills reduces respiratory activity because of the inability of the gill surfaces to actively carry out gaseous exchange, thus the recorded mortalities. The result of the water quality of the media was within the optimal range recorded

by FAO (2000) and Omoregie et. al. (2009) as requirements for C. gariepinus culture implied that the parameters did not seem to influence the toxicity of the pesticide to the test fish. Mortality observed during the acclimation must have been due to stress at handling and transportation from the fish farm to the experimental laboratory. Omoniyi et. al. (2002) made similar observations.

22

The fish exhibited stressful behaviours which were higher as the concentration of toxicant increased. There was a gradual decrease with time until a state of calmness, which was subsequently followed by death. A similar pattern of behaviour was reported by Fafioye et. al. (2001) on C. gariepinus and Rahman et. al. (2002) on C. punctatus. The observed restlessness and uncoordinated swimming in bioassay media might be due to the effect of trichlorvos which is a stimulant in the pesticide.

Dichlorvos was specifically identified to inhibit cholinesterase enzymes (Umar et. al., 2010). It could bind on to acetylcholine receptors in the nervous system thus causing the excitation and the resultant jumping and restlessness. Bleached bodies with lesions were indicative of damage caused by DDVP. Fafioye et. al. (2001) reported that skin abnormalities such as lesions could expose the fish flesh to various other diseases. Omoregie et. al. (1990) had made a similar observation.

The LC50 of DDVP to the fingerling stage of C. gariepinus was lower than that of the juvenile but the value was still higher than the 96-hr LC50 values reported for other organophosphate pesticides (Omonregie et. al., 1990; Rahman et. al., 2002 and Omitoyin et. al., 2006). The values of LC50 and LT50 on both developmental stages of C. gariepinus indicated that the pesticide exerted lethal effects more on the fingerling than the juveniles. The result even showed 1.79 times more toxicity to the fingerling than the juveniles probably due to the physiological and structural fragility differences of the two stages.

The abnormalities in behaviour and mortalities of C. gariepinus as a result of exposure to the DDVP pesticide under laboratory conditions suggest that the use of Dichlorvos by farmers, fisherfolk and other Nigerians be banned to preserve the lives of

Croatian Journal of Fisheries, 2013, 71, 19-24 I. T. Omoniyi et. al.: Toxicity of Dichlorvos on Clarias gariepinus

non-target organisms, especially the fishes in the water bodies. This pesticide is highly poisonous to fish and its public awareness should be enhanced in the country.

Sažetak lEtalno djElovanjE 2,2-diklorovinil dimEtil fosfata (ddvp) na mlaĐ i mladuncE vrstE Clarias gariepinus (burcHEll, 1822) Ovim istraživanjem proučavano je letalno djelovanje 2,2-diklorovinil dimetil fosfata (DDVP) za mlađ (srednja masa 7,02 ± 2,56 g) i mladunce (srednja masa 13,54 ± 1,46 g) afričkog soma Clarias gariepinus u statičnoj obnovljivoj bioanalizi. DDVP (Dichlorvos) je organofosforni pesticid. Svaki tretman letalnog djelovanja vršio se u tri ponavljanja s testnim koncentracijama otopine (mlađ: 0, 250, 275, 300, 325 μgL-1) i (mladunci: 0, 400, 450, 500, 600 μgL-1). Prikupljani su podaci o smrtnosti ribe kao i fizikalno-kemijski parametri vode (temperatura, pH, otopljeni kisik i električna provodnost, EC) te se potom primjenjivala jednosmjerna analiza varijance (ANOVA) s 5% vjerojatnosti. Korišten je Duncan Multiple Range Test (DMRT) kako bi se razdvojile razlike između srednjih vrijednosti. Srednja letalna koncentracija (LC50) i srednje vrijeme smrtnosti (LT50) određeni su probit analizom. Parametri kvalitete vode bazena nisu pokazivali značajnu razliku od kontrolnih, osim za provodljivost i pH. Ponašanje riba se očitovalo u nepravilnom i nekoordiniranom plivanju koje je bilo naglašenije kod mladunaca. Izbijeljeno tijelo je jedina uočena vanjska promjena, a bila je naglašenija kod mlađi. 96-satne vrijednosti LC50 za mlađ i mladunce iznosile su 275,2 μgL-1, odnosno 492,0 μgL-1. Vrijednosti LT50 za mlađ su bile 48,10 i 7,77 sati za koncentracije 250 μgL-1, odnosno 325 μgL-1; dok su za mladunce bile 25,54 i 5,34 sati za 400 μgL-1, odnosno 600 μgL-1. Rezultati su pokazali da je DDVP 1,79 puta više toksičan za mlađ nego za mladunce.

Ključne riječi: Dichlorvos, toksičnost, Clarias gariepinus, LC50 , LT50

rEfErEncEs Agbon, A. O., I. T. Omoniyi and Teko, A. A. (2002): Acute toxicity of tobacco (Nicotiana tobaccum) leaf dust on Oreochromis niloticus and haematological changes resulting from sub-lethal exposure. Journal of Aquatic Sciences, 17(1):5-8.

Agbon, A. O., I. T. Omoniyi, F. I. Adeosun, W. O. Abdul and C. A. Agbon (2010): Fish Trading: A tool for socio-economic enhancement and poverty alleviation. In: Ansa, E. J., Fashina-Bombata, H. A. and Ndimele, P. E (eds.). proceeding of the 25th Annual Conference & Fair of the Fisheries Society of Nigeria (FISON). Pp 564-568.

Asonye, C. C., Okolie, N. P., Okenwa, E. E. and Iwuanyawu, U. G. (2007): Some physic-chemical characteristics and heavy metal profiles of Nigerian rivers, streams and waterways. African Journal of Biotechnology, 6(5): 617-624.

Fafioye, O. O., Adeogun, O. A., Olayinka, E. A. and Ayoade, A. A. (2001): Effect of sub-lethal concentrations of lead on growth of Clarias gariepinus.

Nigerian Experimental Biology, 5(1): 61-68.

FAO (2000): Manuals of methods in aquatic environment Research. Part 9.analysis of metals and organochlorines in fish. Fish Technical Paper 212.

Fawole, O. O., Ogundiran, M. A., Ayandiran, T. A. and Olagunju, O. F. (2007): Proximate and mineral composition in some selected freshwater fishes in Nigeria. Journal of Food Safety, 9: 52-55.

Idi-Ogede, A. M. (2012): Toxicity of 2,3- Dichlorovinyl Dimethyl Phosphate (Sniper 1000EC) in Clarias gariepinus and Oreochromis niloticus under laboratory conditions. Ph.D Thesis, Federal University of Agriculture Abeokuta, Nigeria. 237pp.

Joshi, P. K., Harish, D. and Bose, M. (2002): Effect of Lindane and Malathion exposure to certain blood parameters in a freshwater teleost fish, Clarias batrachus. Pollution Resources, 21(1): 55-57.

Omitoyin, B. O., Ajani, E. K. and Fajimi, A. O. (2006): Toxicity of Gramoxone (Paraquat) to juvenile African catfish, Clarias gariepinus (Burchell, 1822). American-Euroasian Journal of Agriculture and Environmental Sciences, 1(1): 26-30.

Omoniyi, I. T., Agbon, A. O. and Sodunke, S. A. (2002): Effect of lethal and sub-lethal concentrations of tobacco (Nicotiana tobaccum) leaf dust extract on weight and haematological changes in Clarias gariepinus (Burchell). J. Appl. Sci. Environ.

Mgt., 6(2): 37-41.

Omoregie, E., Malachy, N. O., Ajino, I., Romanus, I. and Kazimierz, W. (2009): Effect of single super-phosphate fertilizer on survival and respiratory dynamics of Oreochromis niloticus. Acta Ichthyological et Piscatoria, 39(2): 103-110 Omoregie, E., Ufodike, E. B. C and Keke, I. (1990): Tissue chemistry of Oreochromis niloticus exposed to sub-lethal concentrations of Gammalin 20 and Acetellic 25EC. Journal of Aquatic Sciences, 5: 33-36.

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Croatian Journal of Fisheries, 2013, 71, 19-24 I. T. Omoniyi et. al.: Toxicity of Dichlorvos on Clarias gariepinus

Rahman, M. Z., Hossain, Z., Mollaqh, M. F. A. and Ahmed, G. U. (2002): Effect of Diazinon 60EC on Testudineus (C. punctatus and B. gonionotus). The ICLARM Quarterly, 25(2): 8-12 Umar, M., Stephen, S. H., Abdullahi, M. and Garba, M. (2010): Dichlorvos concentrations in locally

24

formulated pesticide (Ota-piapia) utilized in Northeastern Nigeria. Scientific Research and Essay, 5(1): 049-054.

Wardlaw, A. C. (1985): Practical Statistics for Environmental Biologists. John Wiley & Sons.

New York USA. 290pp.

Croatian Journal of Fisheries, 2013, 71, 25-31 K. M. Adamu et. al.: Selected Liver and Kidney Biochemical profiles

CODEN RIBAEG ISSN 1330-061X

PRELIMINARY COMMUNICATION

sElEctEd livEr and kidnEy biocHEmical profilEs of Hybrid catfisH ExposEd to JaTropHa CurCas lEaf dust kabir m. adamu*, m. c. isah, t. a. baba, t. m. idris Department of Biological Sciences, Ibrahim Badamasi Babangida University, P.M.B. 11, Lapai, Nigeria, tel: +234(0)8035826075 * Corresponding Author, E-mail: kabrmoh@yahoo.com

ARTICLE INFO

ABSTRACT

Received: 6 March 2012 Received in revised form: 15th December 2013 Accepted: 28th February 2013 Available online: 29th March 2013

This study investigated the effect of sublethal concentrations (7.50, 5.00, 2.50 and 0.00 g\L (control)) of Jatropha curcas leaf dust on some liver and kidney biochemical profiles such as total protein, total bilirubin, total albumin and total globulin of hybrid catfish (Clarias gariepinus (♀) and Heterobranchus bidorsalis (♂)) after a 14-day experimental period. The result was significantly different in the mean value of determined liver total bilirubin, while total protein, albumin and globulin were insignificantly different in the exposed fish compared with the control. The kidney revealed varying levels of insignificant difference in its level of total protein, total albumin, total bilirubin and total globulin.

Therefore, this investigation has revealed that sublethal concentration of Jatropha curcas has no effect on the basic function of the determined biochemical profiles of hybrid catfish and that the changes were directly proportional to J. curcas concentration.

th

Keywords: Jatropha curcas, Hybrid catfish, Liver, Kidney, Biochemical profile

introduction Plants are virtually inexhaustible source of structurally diverse and biologically active substance (Ujváry, 2000). Jatropha curcas (linn) or physic nut or Kashia Bukun in Nupe language is found growing on uncultivated land in central Nigeria. It is a tropical plant that can be grown in low to high rainfall areas, thus can be used to reclaim land as a hedge and as a commercial crop. J. curcas plant has a caustic milky sap and toxic seed. It is one amongst many in family Euphorbiaceae with wide range of medical importance in Nigeria (Fajas et al., 1986 and Igoli et al., 2005). The bark is used as fish poison and the oil from seed is used as bio-diesel (Achten et al., 2008). However, Makkar and Becker, (1998) reported some toxins and anti-nutritive compounds such as curcin, tannins, phytates, flavonoids, saponins, vitexine, cyanide and trypsin inhibitor in the plant.

Its seed are considered highly nutritious and could be exploited as a rich and economical protein supplement in animal feed (Makkar et al., 1998). J.

curcas, which was found growing in semi arid, arid and tropical environments, contains various antinutrients which if properly processed could be used to replace most conventional feedstuffs (groundnut cake, soybean cake and cotton seed cake, etc.)

(Belewu et al., 2010).

Hybrid catfish is the hybrid catfish Clarias gariepinus (♀) and Heterobranchus bidorsalis (♂). They are desirable food worldwide. The choice of the test catfish in this study was attributed to the fact that in order to extrapolate meaningful, relevant and ecologically significant results from aquatic toxicity test, not only appropriate test but also appropriate organism should be used. Hybrid cattish constitutes one of the main fish species of economic importance in Nigeria and elsewhere in the developing world, thus its use in this study.

Studies on the characterizations of J. curcas include Tint and Mya (2009), Demissie and Lele, (2010) and Abdurrahman and Oladele, (2011). The effect of J. curcas has been previously studied on different organisms (Adam 1974, Adam and Magzoub, 1975, 25

Croatian Journal of Fisheries, 2013, 71, 25-31 K. M. Adamu et. al.: Selected Liver and Kidney Biochemical profiles

Liu et al., 1997, Makkar et al., 1998, Chivandi et al., 2006, Goel et al., 2007, Igbinosa et al., 2009, Awasthy et al., 2010, Dheeraj et. al., 2010, Arekemase et al., 2011, Abo et al., 2011 and Musa et al., 2011), but none have reported its effect on the liver and kidney biochemical profiles of hybrid catfish. Thus this research was poised to ascertain the effect of J. curcas leaf dust at sublethal concentrations on selected liver and kidney biochemical profiles such as total protein, total albumin, total globulin and total bilirubin of hybrid catfish in a static semi-renewable bioassay system after a 14-day exposure period with the objective to determine the involvement of these examined biochemical profiles in environmental monitoring and health condition of the experimental fish, and to provide information on the sublethal effects of the plant material on the examined biochemical profiles of the test fish.

matErials and mEtHods Hybrid catfish was chosen because of the position it occupied within the food chain; it is amenable to laboratory conditions/testing, shows genetic stability thus uniform population can be tested; it is produced artificially and commands high preference by consumers. Juvenile of the fish, mixed sex and the same brood stock of mean weight (9.701.17 g) were obtained from Makolo Fish Farm in Chanchaga, Local Government Area of Niger State, Nigeria.

They were transported to the Department of Biological Sciences Laboratory, Ibrahim Badamasi Babangida University, Lapai in the morning hours (08:30 – 09:00) in a large plastic container. The fish were held in the laboratory in large glass aquaria of 80 L capacity with clean borehole water. They were then acclimatized for 14 days during which they were fed to satiation with commercial fish feed pellets (Copens 2.0 mm) twice daily. Leftover feed and faces were siphoned off promptly and dead fish were promptly removed to avoid contamination. The percentage of death fish recorded during acclimatization was less than 1%, as such the fishes were accepted as being adapted to the laboratory conditions. They were then transferred to the experimental plastic aquaria (ten (10) fish/40 L aquaria) in two replicates.

The leaves of J. curcas were obtained from Patigi in Patigi local Government Area of Kwara State, Nigeria. The collected leaf samples were air-dried for 21 days, grounded into powder with the use of laboratory mortar and pestle therefore sieved and stored in a sealed plastic container until required.

The concentrations used for the experiment were 7.50, 5.00, 2.50 and 0.00 g/L which were obtained after preliminary investigation. These concentrations 26

were introduced in four (4) sets of aquaria with two replications.

Each of the ten (10) juvenile fish were placed in the 40 L glass aquarium. Bore-hole water was used during the acclimatization and exposure period. Feeding regime (08:00 and 18:00 hours) during exposure period was the same as that of the acclimatization period. In order to monitor the toxicant strength, level of dissolved oxygen, the effects of evaporation, Ammonia concentration and reduced stress during experimentation, the test media were replaced by 50% prepared concentrations of the same quality, after removing its equivalent along with undigested food and defecation every 48 hours to maintain the requisite level and potency of the concentration. The exposure period lasted for fourteen (14) days. At the start (0 hour) of the experiment, the sum total of ten fish were sacrificed and analyzed for the biochemical profiles. The water quality parameters of the experimental water used were 25.20±0.24oC, pH 7.15±0.12, dissolved oxygen 9.21±0.32 mgl-1 and total alkalinity 27.89±0.41. At the end of the 14-day experimental period, fifteen fishes were sacrificed from each concentration where liver and kidneys were removed from the fish and pulverized in a laboratory mortar and pestle separately while extractions were prepared by adding 2 ml of 10% sucrose solution before been centrifuged (Mahobia, 1987) and stored in another test-tube in the refrigerator until analysis.

Total protein was determined in accordance to the principle of Tietz (1995), total albumin by colorimetric method of Doumas et al. (1971) and total bilirubin by colorimetric method of Sherlock (1951), thereof their absorbance (A) was read against the blank using a spectrophotometer (20D PEC Medicals, U.S.A).

All data were presented as means ± standard error, the data from the 14-day J. curcas leaf dust exposure were first analyzed using a one-way (concentration) analysis of variance, after which individual means were compared using Bonferoni multi-sample correction/test. Control values obtained at the beginning and the end of the 14-day exposure period were not significantly different (p>0.05) and were therefore combined as one control. In all cases, differences were considered statistically significant at either p<0.01 or p<0.05.

rEsults The changes in biochemical profiles (total protein, albumin, bilirubin and globulin) recorded in the test fish following exposure to the various sublethal concentrations of J. curcas leaf dust after the 14-day exposure period are as presented herein.

Croatian Journal of Fisheries, 2013, 71, 25-31 K. M. Adamu et. al.: Selected Liver and Kidney Biochemical profiles

The mean values of total protein (g/dL) in the liver and kidney of hybrid catfish exposed to sublethal concentrations of J. curcas leaf dust after the 14day exposure period were presented in Fig. 1a and b respectively. There was an insignificant (p>0.05) increase and decrease in the liver and kidney total protein values respectively when compared with the control group.

The mean values of total albumin (g/dl) in the liver and kidney of hybrid catfish exposed to sublethal concentrations of J. curcas leaf dust after the 14day exposure period were presented in Fig. 2a and b respectively. There was an insignificant (p>0.05) decrease in the level of liver and kidney total albumin values with 5.0 g/L showing insignificant (p>0.05) increased values.

Fig 1: The mean total protein (g/dL) value of hybrid catfish after 14-day exposure period to sublethal concentrations of J. curcas leaf dust. Each point represents the mean and vertical bars indicate the standard error of the mean. a=liver, b=kidney

Fig 2: The mean total Albumin (g/dL) value of hybrid catfish after 14-day exposure period to sublethal concentrations of J. curcas leaf dust. Each point represents the mean and vertical bars indicate the standard error of the mean. a=liver, b=kidney 27

Croatian Journal of Fisheries, 2013, 71, 25-31 K. M. Adamu et. al.: Selected Liver and Kidney Biochemical profiles

The mean value of total globulin (g/dL) in the liver and kidney of hybrid catfish exposed to sublethal concentrations of J. curcas leaf powder after the 14-day exposure period was presented in Fig. 3 a and b respectively. There was an insignificant (p>0.05) increase and decrease in the liver and kidney total globulin values respectively.

The mean values of total bilirubin (g/dL) in the liver and kidney of hybrid catfish exposed to sublethal concentrations of J. curcas leaf dust after the 14day exposure period was presented in Fig. 4 a and b respectively. There was an insignificant (p>0.05) and significant (p<0.05) increase in the kidney and liver total bilirubin values respectively.

Fig 3: The mean total globulin (g/dL) value of hybrid catfish after 14-day exposure period to sublethal concentrations of J. curcas leaf dust. Each point represents the mean and vertical bars indicate the standard error of the mean. a=liver, b=kidney

Fig 4: The mean total bilirubin (g/dL) value of hybrid catfish after 14-day exposure period to sublethal concentrations of J. curcas leaf dust. Each point represents the mean and vertical bars indicate the standard error of the mean and the asterisk represents a significant difference between the control and experimental group at 0.05 level a=liver, b=kidney

28

Croatian Journal of Fisheries, 2013, 71, 25-31 K. M. Adamu et. al.: Selected Liver and Kidney Biochemical profiles

discussion

Sažetak

Biochemical profiles such as total protein, albumin, globulin and bilirubin could be used as Biomarker (Barnhoorn and Van Vuren, 2004). Total protein is a vital constituent of all cells and tissues. It plays a vital role in the determination of the physiological phases of a cell. All biological activities are regulated by enzymes and hormones, which are also proteins. The insignificant increase in liver total protein may be due to a high demand of protein to metabolize the plant content or due to hemo-concentration arising from fluid loss (Awasthy et al., 2010). Thereof the quantity of total protein is dependent on the rate of protein synthesis or on the rate of its degradation; resulting in the decrease of kidney total protein thus consequent impairment in protein synthesis machinery (Adamu et al., 2008).

This might also be a result of a higher demand from the body to counter stress, which triggers protein metabolism.

Albumin functions as transport proteins for several steroid hormones and for fatty acids from adipose tissue to muscle. It is responsible for about 80% of the total osmotic regulation.

The increased value of liver albumin at concentration of 5.0 g/l could be a result of accumulation of protein in the liver impeding other function of the liver, and the decrease in the value of liver albumin at 7.5 g/l may be due to fluctuation or instability in the protease which impede its function of transportation. The corresponding decrease in the value of kidney total albumin may be a result of J. curcas impeding its function of transportation (Adamu and Kori-Siakpere, 2011) or a result of inhibitory effect of the leaf powder on protein hydrolytic activity due to elevation of protease activity that corresponds with the values of total protein (Fafioye et al., 2005).

The increased value of liver globulin showed the effect of J. curcas leaf powder as an inhibitory agent on hydrolytic activity due to the elevation of protease activity in the liver (Adamu and KoriSiakpere, 2011), thus decreased kidney total globulin values.

Bilirubin is a metabolic waste product which is important in the evaluation of liver function. The insignificance increase in bilirubin may be correlated to the destruction of red blood cells by the plant contents as reported by Adamu and Audu (2008).

odabrani jEtrEni i bubrEŽni biokEmijski profili HibridnoG soma iZloŽEnoG lisnom praHu JaTropHa CurCas Ova studija istražuje učinak subletalnih koncentracija (7,50, 5,00, 2,50 i 0,00 g\L (kontrola)) lisnog praha Jatropha curcas na neke jetrene i bubrežne biokemijske profile, kao što su ukupni protein, ukupni bilirubin, ukupni albumin i ukupni globulin hibridnog soma (Clarias gariepinus (♀) i Heterobranchus bidorsalis (♂)), nakon četrnaestodnevnog eksperimentalnog razdoblja. Rezultat se značajno razlikovao u srednjoj vrijednosti određenog jetrenog ukupnog bilirubina, dok se ukupni protein, albumin i globulin nije značajnije razlikovao u promatranoj ribi u usporedbi s kontrolnom. Bubreg je pokazao promjenjivi raspon malih razlika (p>0,05) u razini ukupnog proteina, ukupnog albumina, ukupnog bilirubina i ukupnog globulina. Prema tome, ovim se istraživanjem utvrdilo da subletalne koncentracije J. curcas nemaju učinka na osnovne funkcije određenih biokemijskih profila hibridnog soma te da su promjene izravno proporcionalne koncentracijama J. curcas.

Ključne riječi: Jatropha curcas, hibridni som, jetra, bubreg, biokemijski profil

rEfErEncEs Abdulrahaman, A.A., Oladele, F.A. (2011): Response to Trichomes to water stress in two species of Jatropha. Insight Botany, 1, (2), 12-15.

Abo El-fadel M.H., A.M Hussein, A.H. Mohamed (2011): Incorporation of Jatropha curcas meal on lambs ration and its effect on lamb performance. Journal of American Science 7, (2), 129132.

Achten, W.M.J, Verchot, L., Franken Y.J, Mathijs, E., Singh, V.P, Aerts, R., Muys, B. (2008): Jatropha bio-diesel production and use. Biomass and Bioenergy 32, (12), 1063-1084.

Adam, S.E., Magzoub, M. (1975): Toxicity of Jatropha curcas for goats. Toxicology 4, (3), 347354.

Adam, S.E.I. (1974): Toxicity effect of Jatropha curcas on mice. Toxicology 2, (1), 67-76.

Adamu, K.M, Audu, B.S., Audu E.L. (2008): Toxicity and histopathological effect of Portland cement powder in solution on the structure of the gill and 29

Croatian Journal of Fisheries, 2013, 71, 25-31 K. M. Adamu et. al.: Selected Liver and Kidney Biochemical profiles

liver tissues of the Nile tilapia Oreochromis niloticus: A microscopic study; Tropical Freshwater Biology 17, (1), 25-36.

Adamu, K.M., Audu, B.S. (2008): Haematological Assessment of the Nile Tilapia Oreochromis niloticus exposed to sublethal concentrations of Portland cement powder in solution.

International Journal of Zoological Research 4, (1), 48-52.

Adamu, K.M., Kori-Siakpere, O. (2011): Effect of Sublethal concentrations of Tobacco (Nicotiana tabaccum) leaf dust on biochemical parameters of hybrid catfish (Clarias gariepinus and Heterobranchus bidorsalis). Brazilian Archives of Biological and Technology, 54, 183-196.

Arekemase, M.O, Kayode, K.M.O, Ajiboye, A.E (2011): Antimicrobial activity and phytochemical analysis of Jatropha curcas plant against some selected microorganism. International Journal of Biology, 3, (3), 52-59.

Awasthy, V, Vadiamudi, V.P, Koley, K.M, Awasthy, B.K, Singh, P.K, (2010): Biochemical changes after short term oral exposure of Jatropha curcas seeds in wistar rats. Toxicology international, 17, (2), 67-70.

Barnhoorn, I.E., Van Vuren, J.H. (2004): The use of different enzymes in fresh water fish as a tool for the assessment of water pollution in South Africa. Ecotoxicology and Environmental Safety 59, (2), 180-185.

Belewu, M.A, Belewu, K.Y and Ogunsola, F.O. (2010): Nutritive value of dietary fungi treated Jatropha curcas kernel cake: Voluntary intake, growth and digestibility coefficient of goat. Agriculture and Biology Journal of North America 1, (2), 135-138.

Chivandi, E., Erlwanger, K.H., Makuza, S.M., Read, J.S., Mtimuni, J.P. (2006): Effect of dietary Jatropha curcas meal on percent packed cell volume, serum glucose, cholesterol and triglyceride concentration and alpha-amylase activity of weaned fattening pigs. Research Journal of Animal and Veterinary Sciences, 1, (1), 18-24.

Demissie, A.G., Lele, S.S. (2010): Bio-assay assisted identification of phorbol ester from Jatropha curcas (linn) tissue culture. International Journal of Pharma and Bio Sciences, 1, (3), 1-7.

Dheeraj, A., Bharti, A., Kharya, M.D. (2010): Effect of ethanolic extract of Jatropha curcas seeds on estrus cycle of female albino rats. Der Pharmacia Lettre, 2, (6), 146-150.

Doumas, B.T, Watson, W.A., Biggs, H.G. (1971): Albumin standards and the measurement of 30

serum albumin with bromcresol green, Clinica Chimica. Acta 31, (1), 87-96.

Fafioye, O.O., Fagade, S.O., Adebisi, A.A. (2005): Toxicity of Raphia vinifera P. beauv fruit extracts on biochemical composition of Nile tilapia (Oreochromis niloticus, Trewavas). Biokemistri, 17, (2), 137-142.

Fajas F.R., Garia, L.L, Venzon, E.L, Sison, F.M, Villamiera, B.A, Jojas A.J., Liava, I. (1986): Pharmaceutical studies of Jatropha curcas as a possible source anti-arrhythmic (beta bloker) agent. Phillip Journal of Science 115, 317-328.

Goel, G., Makkar, H.P., Francis, G., Becker, K. (2007): Phorbol esters: structure biological activity and toxicity in animals. International Journal of Toxicology 26, (4), 279-288.

Igbinosa, O.O., Igbinosa, E.O., Aiyegoro, O.A. (2009): Antimicrobial activity and Phytochemical screening of stem bark extracts from Jatropha curcas (linn). African Journal of Pharmacy and Pharmacology, 3, (2), 058-062.

Igoli J.O., Ogaji, O.G, Tor Anyiin, T.A., Igoli, N.P (2005): Traditional medicine practice among the Igede people of Nigeria. African Journal Traditional Complimentary and Alternative Medicine, 2, (2), 134-152.

Liu, S.Y., Sporer, F and Wink, F.M. (1997): Anthraquinones in Rheum palmatum and Rumex dentatus (polygonanceae), and phorbol esters in Jatropha curcas (euphobiacea) with mulluscicida) activity against the schistosome vector snails Oncomelania, Biomphalaria and Bulinus.

Tropical Medicine and International Health 2: 179-188.

Mahobia, G.P. (1987): Studies on Indian Cichlids.

Ph.D thesis, University of Science and Technology, Central Marine Fisheries Research Institute, Cochin, India.

Makkar, H.P.S, Aderibigbe A.O. and Becker, K (1998): Comparative evaluation of nontoxic and toxic variety of Jatropha curcas for chemical composition digestibility, protein degredation and toxic factor. Internation Journal of Food Chem.

62(2): 207 -215 Makkar, H.P.S. and Becker, K. (1998): Jatropha curcas toxicity: Identification of toxic Principle (s). In garland T. Barr AC (Eds) toxic plants and other natural toxicants CAB international U.K. (1) PP 554-558.

Musa, A.K., Belowu, M.A., Muhammed-Lawal, A., Adekola, F.O. Olarewaju, B.O., Ibraheem, S.O. (2011): Cost analysis and toxicity of Jatropha curcas on maize weevil Sitophilus zeamaiz mot-

Croatian Journal of Fisheries, 2013, 71, 25-31 K. M. Adamu et. al.: Selected Liver and Kidney Biochemical profiles

sch. African Journal of Plant Science 5, (4), 233236.

Sherlock, S (1951): Liver disease, Churchill London. p.204 Tietz, N.W. (1995): Clinical guide to laboratory tests.

WB Sauder Company, Philadelphia, 3rd edition, 518-519 pp.

Tint, T.K, Mya, M. (2009): Production of biodiesel from Jatropha oil in pilot plant. World Academy of science, Engineering and Technology, 26, 477483.

Ujvรกry I. (2000): Semi-natural products and related substances as alleged botanical pesticides. Pest Management Science, 56, (8), 703-705.

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Croatian Journal of Fisheries, 2013, 71, 32-36 R. Dekić i sur.: Utjecaj temperature na eritrocitni profil babuške

CODEN RIBAEG ISSN 1330-061X

PRETHODNO PRIOPĆENJE

utjEcaj promjEna tEmpEraturE vodE na Eritrocitni profil Carassius gibelio radoslav dekić*1, aleksandar ivanc2, maja mandić1, svjetlana lolić1, azra bakrač-bećiraj3 Prirodno-matematički fakultet, Univerzitet u Banjoj Luci, Mladena Stojanovića 2, 78000 Banja Luka, BiH / Faculty of Natural Sciences and Mathematics, University of Banja Luka, Bosnia and Herzegovina 2 Državni Univerzitet u Novom Pazaru, Vuka Karadžića bb, 36300 Novi Pazar, Srbija / State University of Novi Pazar, Vuka Karadžića bb, 36300 Novi Pazar, Serbia 3 Biotehnički fakultet, Univerzitet u Bihaću, Kulina bana 2, 77 000 Bihać / University of Bihac, Biotehnycal faculty, Kulina bana 2, 77 000 Bihać, BiH * Corresponding Author / Autor za korespodenciju, E-mail: rdekic@yahoo.com 1

ARTICLE INFO / STATUS ČLANKA

SAŽETAK

Received/Primljeno: 15th April 2012 Received in revised form/Korigirano: 16th January 2013 Accepted/Prihvaćeno: 28th February 2013 Available online/Dostupno na internetskoj mreži: 29th March 2013

Istraživanje promjene temperature vode na eritrocitni profil provedeno je na jedinkama babuške (Carassius gibelio) s područja Bardače (BiH). Istraživanjem je obuhvaćeno trideset osam jedinki koje su bile podijeljene u dva akvarija, prilagođene na eksperimentalne uvjete, a potom podvrgnute različitom temperaturnom režimu. Kontrolna grupa jedinki imala je konstantnu temperaturu vode 10 °C, dok je kod tretirane grupe jedinki temperatura vode postupno povećana na 20 °C u periodu od tri dana. Provedena analiza eritrocitnog profila koji obuhvaća: broj eritrocita, koncentraciju hemoglobina, hematokrit, MCV, MCH i MCHC, pokazuje da jedinke koje su izlagane povećanju temperature su imale značajno veće vrijednosti broja eritrocita i hematokrita, dok su jedinke kontrolne grupe imale veće vrijednosti MCH i MCHC.

Ključne riječi: eritrocitni profil, babuška, temperatura

uvod Temperatura predstavlja jedan od najznačajnijih faktora sredine koji utječe na sva živa bića, a čije djelovanje je naročito izraženo kod poikilotermnih organizama. Utječe na niz fizioloških procesa u organizmu mijenjajući brzinu njihova odvijanja.

Slatkovodne ribe su ektotermni oganizmi koji ne mogu regulirati svoju tjelesnu temperaturu fiziološkim sredstvima (Moyle i Cech, 2004) i čija tjelesna temperatura je identična ili približna temperaturi sredine na njihovoj specifičnoj lokaciji. Shodno tome, brzina biokemijskih reakcija u velikoj mjeri ovisi o tjelesnoj temperaturi, kao i svi aspekti fiziologije riba uključujući rast, reprodukciju i aktivnost (Ficke i sur., 2005).

Posljedice povećavanja temperature vode mogu utjecati na individue mjenjajući različite fiziološke 32

funkcije kao i sposobnost za održanje unutrašnje homeostaze nasuprot promjenjivoj spoljašnjoj sredini (Roessig i sur., 2004).

Faktori koji izazivaju stresno stanje kod riba prirodno su povezani sa promjenama fizičkih, kemijskih i bioloških faktora vodene sredine što utječe na povećanu osjetljivost riba prema bolestima (Kubilay i Ulukoy, 2002).

Stoga, istraživanja krvi i tjelesnih tekućina imaju veliki značaj za praćenje zdravlja i kondicije riba kako u prirodnim staništima, tako i u akvakulturi (Ivanc i sur., 2005). Istovremeno hematološki parametri predstavljaju pouzdane indikatore stanja životne sredine (Dekić i sur., 2009).

Cilj rada je ispitivanje utjecaja promjene temperature vode na eritrocitni profil babuške Carassius gibelio (Bloch, 1782).

Croatian Journal of Fisheries, 2013, 71, 32-36 R. Dekić i sur.: Utjecaj temperature na eritrocitni profil babuške

matErijal i mEtodE Utjecaj temperature vode na eritrocitni profil proveden je na jedinkama Carassius gibelio koje su ulovljene na hidrografskom području Bardače (BiH) Nakon izlovljavanja ribe su na transportirane u laboratorij i metodom slučajnog uzorka raspoređene u akvarije zapremine 170 l.

Jedinke su prilagođene na eksperimentalne uvjete, a tijekom perioda adaptacije temperature vode iznosila je 10 °C u oba akvarija. Dnevno je vršeno čišćenje filtera i izmjena 1/3 vode.

Za održavanje potrebne temperature vode korišteni su grijači,,PEAR AQUATICS Y 978’’ (50 Hz, 100 W), dok su za aeraciju i čišćenje vode korištene pumpe,,CHAMPION CX-0098’’(50 Hz, 6 W) sa dva izlaza. Nakon perioda prilagodbe u jednom od akvarija pristupilo se postupnom povećanju temperature vode, koja je treći dan dostigla 20 °C. Svi eksperimentalni zahvati provedeni su u skladu sa nacionalnim propisima o dobrobiti životinja i postupanja sa životinjama tijekom pokusa.

Standardna i totalna dužina su određeni pomoću ihtiometra, dok je masa određena pomoću tehničke vage (Kern 440-33).

Uzimanje krvi za hematološke analize obavljeno je punktiranjem srca oštrom i širokom sterilnom iglom (1,0 do 1,2 mm), uz primjenu pravila sterilnog rada. Krv bez dodatka antikoagulantnog sredstva koristila se za dalju analizu.

Analiza broja uobličenih elemenata određena je postupkom brojanja u komori (hemocitometru) metodom Kekića i Ivanca (1982), dok je za određivanje koncetracije hemoglobina (Hb) korištena Drabkinova hemiglobin cijanidska metoda (Blaxhall i Daisly, 1973).

Hematokrit (Hct) je određen centifugiranjem, korištenjem mikrohematokrit centrifuge, dok su hematološki indeksi dobiveni na osnovu vrijednosti hematokrita, broja eritrocita i koncentracije hemoglobina.

Srednja vrijednost zapremine eritrocita (MCV) računata je putem formule:

Za dobivanje srednje vrijednosti količine hemoglobina u eritrocitu (MCH) korištena je jednadžba:

Srednja vrijednost hemoglobina u litri eritrocita (MCHC) računata je na sljedeći način:

Tablica 1. Deskriptivna statistika i fultonov koeficijent kondicije kontrolnih i termički tretiranih jedinki babuške Table 1: Descriptive statistics and Fulton’s condition factor of control and thermally treated individuals of Prussian carp PARAMETRI/ PARAMETERS

Masa /Weight (g)

Standardna Fultonov koeficijent Totalna dužina/ dužina/ Standard kondicije/ Fulton Total length (cm) length (cm) condition factor

Kontrolna skupina/Control group 87,68 ± 7,31 17,71±0,65 14,39±0,45 2,94±0,14 Srednja vrijednost ± standardna devijacija/ Mean±standard deviation ( ±sd) Minimum/ Minimum 69,26 16,50 13,40 2,67 Maksimum/ Maximum 101,22 18,80 15,40 3,34 Variacioni koeficijent / Coefficient of 8,34 3,66 3,12 4,80 variation (CV) Jedinke izložene povećanju temperature na 20 °C / Individuals exposed to temperature rise to 20 °C 88,47±12,22 17,78±0,85 14,45±0,71 2,92±0,15 Srednja vrijednost± Standardna devijacija/ Mean±standard deviation ( ±sd) Minimum/ Minimum 61,77 16,3 12,9 2,67 Maksimum/ Maximum 113,25 19,2 15,5 3,24 Variacioni koeficijent / Coefficient of 13,81 4,76 4,92 4,97 variation (CV)

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Croatian Journal of Fisheries, 2013, 71, 32-36 R. Dekić i sur.: Utjecaj temperature na eritrocitni profil babuške

Tablica 2. Parametri eritrocitne loze kontrolnih i termički tretiranih babuški1 Table 2: Parameters of erythrocyte lineage of control and thermally treated Prussian1 carps PARAMETRI/ PARAMETERS

Hb (g/l) / Hb (g/l)

Hct (l/l) / PCV (l/l)

Broj erit. (x1012/l) / RBC (x1012/l)

MCV MCH (fl) / MCV (pg) / MCH (fl) (pg)

MCHC g/l erit. / (g Hb/l eryt.)

Kontrolna skupina/Control group 74.66 0.450** 1.046** 438.60 77.16** 172.79 Srednja vrijednost± Standardna ±11.13 ± 0.085 ± 0.196 ±91.49 ± 18.02 ±49.52 devijacija/ Mean±standard deviation ( ±sd) Minimum/Minimum 55.55 0.303 0.730 310.00 36.07 105.02 Maksimum/Maximum 96.29 0.588 1.540 631.51 106.54 262.84 Variacioni koeficijent (CV)/ Coefficient of 14.91 18.94 18.77 20.86 23.36 28.66 variation Jedinke izložene povećanju temperature na 20 °C/ Individuals exposed to temperature rise to 20 °C 76.73 0.545** 1.234** 448.16 63.31** 144.35 Srednja vrijednost± Standardna ±1.47 ± 0.076 ±0.161 ±85.13 ±12.28 ±35.69 devijacija/ Mean±standard deviation ( ±sd) Minimum/ Minimum 55.55 0.333 0.980 297.99 38.23 92.29 Maksimum/Maximum 92.59 0.667 1.550 623.47 84.65 266.93 Variacioni koeficijent (CV)/ Coefficient of 13.65 13.91 13.06 20.00 19.40 24.73 variation 1 Srednje vrijednosti jednog hematološkog parametra obilježenje sa ** su statistički značajno različite (p < 0,05) 1 Mean values of the same hematological parameter marked with ** in superscript are significantly different (p<0.05)

rEZultati i rasprava Istraživanjem je obuhvaćeno 38 jedinki babuške, od kojih je dvadeset jedinki služilo kao kontrola, a osamnaest jedinki bilo izloženo promjenama temperature vode.

Kod svih jedinki pored vrijednosti parametara eritrocitnog profila mjerena je totalna i standardna dužina, masa i Fultonov koeficijent kondicije.

Rezultati su prikazani u tablici 1.

Komparacijom dobivenih vrijednosti za jedinke koje su služile kao kontrola i jedinke koje su izlagane povećanju temperature nisu primjećene značajne razlike. Rezultati deskriptivne statistike parametara eritrocitnog profila prikazani su u tablici 2.

Komparacija rezultata eritrocitnih parametara babuške koja je izlagana različitim temperaturama (kontrolna skupina 10 °C, jedinke izlagane povećanju 20 °C) pokazuje postojanje značajnih razlika kod većine ispitivanih parametara.

Kod jedinki koje su izlagane povećanju temperature primjećene su značajno veće vrijednosti hematokrita (p=0.0009) u odnosu na jedinke koje su služile kao kontrola, zatim vrijednosti broja eritrocita je značajno veća kod jedinki koje su izlagane povećanju temperature vode (p=0.002). Broj eritrocita u krvi riba zavisi od polne aktivnosti, vrste, pola, starosti i godišnjeg doba, kondicije riba, kocentracije kisonika i pH vrijednosti (Bogut i sar., 2006).

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Vrijednost hemoglobina se ne razlikuje značajno kod istraživanih grupa organizama. Također, nisu uočene značajne razlike kod prosječne vrijednosti zapremine eritrocita i prosječne vrijednosti hemoglobina u litri eritrocita.

Međutim, kod jedinki koje su služile kao kontrola vidljivo je da imaju veće vrijednosti prosječne količine hemoglobina u eritrocitu (p=0.009) Gledajući ukupno parametre eritrocitne loze kod kontrolnih i termički tretiranih riba vidljivo je da se kod riba koje su izlagane povećanju temperature vode, povećane vrijednosti broja eritrocita i vrijednosti hematokrita. Istovremeno kod ove grupe jedinki primjećene su nešto veće vrijednosti koncentracije hemoglobina i prosječne zapremine eritrocita, dok kod kontrolnih riba uočene su značajno veće vrijednosti MCH i nešto veće vrijednosti MCHC. Iz prikazanih rezultata proizilazi da se hematološki odgovor ogleda u produkciji stanica u cirkulatornom sustavu što uz povećanje vrijednosti MCV uzrokuje i značajno veće vrijednosti hematokrita.

Također gledajući ukupno jedinki koje su izlagane povećanju temperature vode nešto je i veća koncentracija hemoglobina, ali prema eritrocitima (MCH) i litri eritrocita (MCHC) produkcija je slabija.

Prema Houstonu i sur. (1996) ključni događaj u hematološkom odgovoru na povećanje temperature je zamjena zrelih i ostarjelih eritrocita mladim

Croatian Journal of Fisheries, 2013, 71, 32-36 R. Dekić i sur.: Utjecaj temperature na eritrocitni profil babuške

stanicama koje su metabolički kompetentne imajući u vidu redukciju efikasnosti transporta plinova kod starih eritrocita.

Istraživaja utjecaja termičkog stresa kod jedinki potočne mrene (Barbus balcanicus) pokazuje povećanje vrijednosti prosječne zapremine eritrocita i hematokrita kod termički tretiranih jedinki, dok su vrijednosti MCHC bile znatno veće kod jedinki koje nisu bile izlagane povećanju temperature (Ivanc i sur., 2007).

Osim toga, slična istraživanja provedena su u eksperimentu na tri vrste riba i to: tilapia (Sarotherodon mossambicus), šaran (Cyprinus carpio) i kalifornijska pastrva (Onchorhynchus mykiss). Jedinke korištene u ovom eksperimentu, bile su prilagođavane na laboratorijske uvjete u periodu od dva mjeseca.

Temperatura vode u laboratoriju kretala se oko 19 °C. Nakon dva mjeseca individue svake vrste bile su izložene temperaturama od 15 °C, 20 °C i 25 °C u periodu od tri tjedna.Veće razlike primijećene su između jedinki izloženih na 15 °C i 20 °C nego između jedinki izloženih na 20 °C i 25 °C. Kod tilapije sa porastom temperature raste i srednja vrijednost broja eritrocita, dok su ove vrijednosti kod šarana i pastrve ostale konstantne. Povećanje broja eritrocita nije bilo praćeno kao niti povećanje koncentracije hemoglobina. MCV je bio temperaturno nezavisan kod svih vrsta. Kod šarana su MCH i MCHC temperaturno nezavisni, a kod pastrmke je MCH ostao nepromijenjen. MCH i MCHC su također bili temperaturno nezavisni i kod tilapie, dok je kod pastrve pozitivan odnos bio vidljiv samo za MCHC (Smit i sur., 1981).

Slično istraživanje na jedinkama kalifornijske pastrmke (Oncorhynchus mykiss) provedeno je pri temperaturama od 9 °C i 14 °C. U ovom slučaju istovremeno su praćeni podaci o vrijednostima parametara eritrocitne loze kod jedinki iz ribnjaka koje nisu bile izložene tretmanu.

Na osnovu rezultata primjećeno je da kod riba uzgajanih na 14 °C dolazi do povećavanja prosječne zapremine eritrocita, što uvjetuje veće vrijednosti hematokrita. Također, kod ovih jedinki primjećene su nešto veće vrijednosti koncentracije hemoglobina, a sukladno tome je i količina hemoglobina po eritrocitu veća kod jediki izlaganih temperaturi od 14 °C. To vjerojatno predstavlja adaptaciju na povećavanje temperature vode (Dekić i sur., 2010).

Zaključci 1. Praćene morfometrijske osobine i Fultonov koeficijent kondicije kontrolnih i termički tretiranih jedinki nisu pokazivali značajne razlike; 2. Jedinke koje su izlagane povećanju temperature

imale su značajno veće vrijednosti hematokrita i vrijednosti broja eritrocita; 3. Jedinke koje su služile kao kontrola imale su veće prosječne vrijednosti hemoglobina u eritrocitu (MCH).

Abstract tHE EffEct of tEmpEraturE cHanGE on ErytHrocytE profilE of Carassius gibelio A research on the effect of water temperature change on erythrocyte profile was conducted on Prussian carp (Carassius gibelio) from the Bardača area (BiH).

The study included 38 individuals which were divided into two aquaria, adapted to experimental conditions and then subjected to different temperature regime. The control group had constant water temperature of 10 °C, while for treated fish water temperature was gradually increased to 20 °C for three days. Conducted analysis of erythrocyte profile, which includes erythrocyte count, hemoglobin concentration, packed cell volume, MCV, MCH and MCHC showed that individuals exposed to temperature increase had significantly higher values of erythrocyte count and packed cell volume, while control individuals had higher values of MCH and MCHC. Keywords: erythrocyte profile, Prussian carp, temperature

litEratura Bogut, I., Novoselić, D., Pavličević, J. (2006): Biologija riba. Sveučilište J. J. Strossmayera u Osijeku, Sveučilište u Mostaru.

Dekić, R., Ivanc, A., Bakrač-Bećiraj, A.(2009): Hematološki parametri kao indikatori stanja životne sredine. IV međunarodna konferencija „Ribarstvo“, Zbornik radova, Poljoprivredni fakultet Univerziteta u Beogradu.

Dekić, R., Ivanc, A., Mirošljević, D. (2010): Eritrogram kalifornijske pastrmke (Oncorhynchus mykiss) iz ribnjačkih i eksperimentalnih uslova. II simpozijum biologa Republike Srpske, 4-6. 11. 2010.

Banja Luka. Zbornik sažetaka, 88.

Ficke, A. A., Myrick, C. A., Hansen, L. J. (2005): Potential Impacts of Global Climate Change on Freshwater Fisheries, WWF- World Wide Fund for Nature, Colorado, USA, 91pp.

Ivanc, A., Hasković, E., Jeremić, S., Dekić, R. (2005): Hematological Evaluation of welfare and health of fish, Praxis veterinaria 53 (3) 191-202, 2005.

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Croatian Journal of Fisheries, 2013, 71, 32-36 R. Dekić i sur.: Utjecaj temperature na eritrocitni profil babuške

Ivanc A., Dekić R., Hasković E., Dulčić J., Glamuzina B., Mitrašinović M., Suljević D. i Bubić M. (2007): The effects of thermal stress on red blood cell parameters of Barbus peloponnesis. ECI XII, XII Europen Congress of Ichthyology, Cavtat (Dubrovnik), Croatia, Septembar, 2007.

Kubilay, A., Ulukoy, G. (2002): The effects of Acute Stress on Rainbow Trout (Oncorhynchus mykiss).

Turk J Zool. 26 (2002) 249-254.

Roessig, J.M.; Woodley, C.M.; Cech, J.J.; Hansen, L.J.(2004): Effects of global climate change on marine and estuarine fishes and fisheries. Reviews in Fish Biology and Fisheries, 14: 251-275.

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Smit, G. L., Hattingh, J. and Ferreira, J. T. (1981): The physiological responses of blood during thermal adaptation in three freshwater fish species. J. Fish Biol. 19: 147-160.

Houston, A.H., Dobric, N. and Kahurananga, R. (1996): The nature of hematological response in fish. Studies on rainbow trout Oncorhynchus mykiss exposed to simulated winter, spring and summer conditions. Fish Physiology and Biochemistry. 15, 4: 339-347.

Moyle P. B. and. Cech, J. J. (2004): Fishes: An Introduction to Ichthyology, 5th ed. Prentice Hall, Emglewood Cliffs, N. J.

Croatian Journal of Fisheries, 2013, 71, 37-41 Jawad, L. A.: Otolith mass asymmetry in Carangoides caeruleopinnatus

CODEN RIBAEG ISSN 1330-061X

SHORT COMMUNICATION

otolitH mass asymmEtry in CarangoiDes CaerulepinnaTus (rĂ&#x153;ppEll, 1830) (family: caranGidaE) collEctEd from tHE sEa of oman laith a. jawad Natural Sciences, Auckland War Memorial Museum, Tamaki Paenga Hira, The Domain, Private Bag 92018, Victoria Street West, Auckland 1142, New Zealand * Corresponding Author, E-mail: laith_jawad@hotmail.com

ARTICLE INFO

ABSTRACT

Received: 31th October 2012 Received in revised form: 26th December 2012 Accepted: 28th February 2013 Available online: 29th March 2013

The sagittae mass asymmetry was studied in the teleost Carangoides caeruleopinnatus. The value of the asymmetry was calculated as the difference between the mass of the right and left paired otoliths, divided by average otolith mass. The results show that the absolute value of X in C. caeruleopinnatus does not depend on fish length and otolith growth rate, as it does in other symmetrical fish species. However, the absolute value of otolith mass difference increases with the fish length. The value of x falls between -0.2 and +0.2.

Keywords: Otolith, mass asymmetry, Carangoides caeruleopinnatus, Sultanate of Oman

introduction Usually, when fish experience weightlessness or if there are mass asymmetries in their otoliths, they show significant changes in their behaviour (Egorov and Samarin, 1970; Hoffman, 1977; Von Baungarten et al., 1982; De Jong et al., 1996; Hilbig et al., 2002; Rehman and Anken, 2002; Lychakov and Rebane, 2004). As a result of such a phenomenon, dramatic changes happen to the acoustic functionality of fish.

When otolith mass asymmetry occurs, the incompatibility and incongruity of the right and left otolith movement get affected directly as a result of such changes (Lychakov and Rebane, 2005; Lychakov et al., 2006). Furthermore, a significant impairment to the vestibular and auditory functions becomes evident, but the exact quantitative, morphological and physiological basis of otolith asymmetry is still unclear (Lychakov et al., 2006).

Usually, the symmetrical fish species have a range value for the otolith mass asymmetry of -0.2< x < +0.2 or < 20% (Lychakov, 1992; Lychakov et al., 1988; Lychakov and Rebane, 2004, 2005; Takabayashi, 2003). In addition, previous studies

did not find a relationship between the magnitude of otolith mass asymmetry and length or weight of the fish. Hence, otolith mass fluctuation might be considered the reason behind such an effect (Lychakov and Rebane, 2004, 2005). Moreover, in symmetrical fish species, when otolith mass asymmetry falls well below critical values, the functional impairment does not occur (Lychakov and Rebane, 2005; Lychakov et al., 2006). Egorov and Samarin (1970), Lychakov (1992), Samarin (1992), Lychakov (2002) and Scherer (2001) have stated that the mass of right and left paired otoliths were not generally equal and the otolith mass differences, or what is known as mass asymmetry of the otoliths, could be one of the important factors that affect the quality of acoustic reception in fishes.

Jawad et al. (2010, 2011) are the only two studies on the fishes of Oman investigating otolith mass asymmetry. Thus, the present work will add information to the field of fish research in Oman. The aim of this current study is to quantify and compare the otolith mass asymmetry range and to assess the variability of otolith asymmetry during growth of Carangoides caeruleopinnatus.

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Croatian Journal of Fisheries, 2013, 71, 37-41 Jawad, L. A.: Otolith mass asymmetry in Carangoides caeruleopinnatus

matErials and mEtHods Specimens of C. caeruleopinnatus (150 individuals, 300 otoliths) were collected from the coasts of Muscat City in the Sea of Oman during the period 2009-2010. Total length was measured following the procedure given in Jawad et al. (2010, 2011) prior to removal of otoliths. The auditory capsules were dissected to remove the otoliths which were rinsed in distilled water, air-dried at room temperature for few days and weighed on a Sartorius TE 313S analytical balance to an accuracy of 0.0001 g.

The formula x = (MR – ML) M-1 was used to calculate the otolith mass asymmetry (x), where MR and ML are the otolith masses of the right and left paired otoliths and M is the mean mass of the right and left paired otoliths.

Absence of asymmetry {Mass of the right otolith (MR) - Mass of the left otolith (ML)} occurs when the value of x varies between -2 and 2, and x = 0, whereas x = -2 or x = 2 represent the maximal asymmetry (absence of one otolith). A larger otolith on the right side gives positive value of x and a negative sign means the opposite. The relation between species absolute value of |x| and the species otolith growth rate was examined. The absolute value of the species otolith mass asymmetry was calculated as the average individual value. To evaluate otolith growth rate the relationship between otolith mass and fish length, m = a x l + b, was calculated where, l is the total length of the fish, “a” is the coefficient characterizing the growth rate of the otolith, and “b” is a constant for the species in question.

rEsults The mean value of x is 0.0632+ 2.4105, n = 150 (Fig. 1) and the absolute value of the otolith mass asymmetry IXI is 0.0886 + 0.2418, n = 150 (Fig. 2).

Table 1. Total length and mass of the otolith of Carangoides caeruleopinnatus Total length (mm) 202 209 210 213 213 215 215 217 218 218

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Mass of the otolith (g) Left side Right side 0.0068 0.0067 0.0086 0.0079 0.0078 0.0075 0.0111 0.0113 0.0088 0.0088 0.0218 0.0109 0.0074 0.0072 0.0094 0.0090 0.0115 0.0114 0.0097 0.0085

Table 1. Continued Total length (mm) 220 223 225 226 227 228 230 230 232 236 238 238 238 239 239 240 240 240 240 240 240 242 242 243 245 245 245 250 250 253 253 256 256 258 260 262 265 274 280 286 286 288

Mass of the otolith (g) Left side Right side 0.0096 0.0091 0.0099 0.0097 0.0100 0.0100 0.0118 0.0118 0.0096 0.0100 0.0097 0.0098 0.0097 0.0100 0.0115 0.0111 0.0082 0.0085 0.0093 0.0105 0.0193 0.0185 0.0990 0.0106 0.0102 0.0108 0.0107 0.0103 0.0090 0.0092 0.0172 0.0170 0.0106 0.0100 0.0106 0.0100 0.0130 0.0123 0.0105 0.0106 0.0097 0.0101 0.0125 0.0127 0.0105 0.0109 0.0100 0.0102 0.0151 0.0142 0.0106 0.0108 0.0099 0.0094 0.0105 0.0103 0.0106 0.0103 0.0132 0.0138 0.0140 0.0140 0.0235 0.0222 0.0139 0.0133 0.0117 0.0113 0.0178 0.0172 0.0221 0.0216 0.0198 0.01094 0.0146 0.0152 0.0201 0.0211 0.0194 0.0197 0.0189 0.0174 0.0266 0.0260

According to the regression analysis there was no relationship between fish length and both IXI (y = 0.0166x - 0.313) (P > 0.05, R2 = 0.0272) and x (y= -0.0168x + 0.3444) (P > 0.05, R2 = 0.0263). The relation between otolith mass difference (MR – ML) and fish length was more complex than the relation between x and fish length (n = 150, total length = 202-313 mm, P > 0.05, y = -0.0002x + 0.0027, R2 = 0.0016) (Fig. 3).

Croatian Journal of Fisheries, 2013, 71, 37-41 Jawad, L. A.: Otolith mass asymmetry in Carangoides caeruleopinnatus

Figure 1. Saccular otolith mass asymmetry (x) in Carangoides caeruleopinnatus as a function of fish length

Figure 2. Absolute otolith mass asymmetry(IXI) as function of fish total length

Figure 3. Saccular otolith mass difference in Carangoides caeruleopinnatus as a function of fish length. R & L= right and left side otolith mass

discussion The value of x obtained for the species in question falls between -0.2 and +0.2 as in other marine fish species (Lychakov et al., 2008). The value of mass asymmetry of the saccular otolith obtained for large number of marine species is usually less than 0.05 (Lychakov et al., 2006). This value coincides with the value of mass asymmetry obtained for C.

caeruleopinnatus in the present work and did not depend on otolith growth rate. In both symmetrical roundfish and asymmetric flatfish species, there are no apparent differences in x between benthic, littoral and pelagic fishes (Lychakov et al., 2006).

Unlike for the littoral and bottom fish species, saccular otolith mass difference for pelagic fish species does not increase with the fish length (Lychakov and Rebane, 2004). Otolith mass asymmetry is considered as one of the causes of reduced acoustic and vestibular functionality of fishâ&#x20AC;&#x2122;s ear. This fact was determined by Lychakov and Rebane (2004, 2005) through the mathematical modelling they wrote.

The value of IXI is shown to be low (<0.5), irrespective of fish length, in the majority of fishes studied (Lychakov et al., 2006), which is also true for the species at hand. When asymmetry appears in the utricular and lagenar otolith organs of symmetric fish species, it happens infrequently. In theory, only fishes with largest otolith and with IXI >0.5 will experience difficulty in sound reception due to incompatibility and incongruity of the movement of the two otoliths (Lychakov and Rebane, 2005). Thus, with otolith mass asymmetry below critical value, most fish species can avoid functional disability.

One of the results obtained in the present work is that the saccular otolith mass asymmetry does not depend on fish size. This is consistent with the results of other studies on marine and freshwater fish species (Lychakov and Rebane, 2004, 2005; Lychakov et al., 2006, Jawad et al., 2010, 2011). The mathematical model of Lychakov et al. (2006) has shown that the value of x might be stable during the life of fish, however, it is unknown how fish manage to keep the value of their otolith asymmetry at a low level (Lychakov et al., 2006). Rahmman and Anken (2002) proposed that a monitoring agent acts on the growth of the otolith via negative feedback loop between the brain and the inner ear. Weight of the otolith on the sensory epithelium is found to be this monitoring agent. But other evidence disagrees with this hypothesis, and otolith weight seems not to be involved in the regulation of its growth (Luchakov, 2002).

In the present work, there is no relationship between fish length and otolith mass difference, as this relationship is more complex. This is in agreement with the results obtained by Lychakov and Rebane (2004, 2005) and Jawad et al. (2010, 2011) on several fish species. Lychakov et al. (2006) suggested three reasons for the absence of relationship: (1) small sample size plays a vital role in this study; (2) narrow range of variation in the specimen size; and (3) feasible genetic factors. These suggestions are evident in the data of the species in question as 39

Croatian Journal of Fisheries, 2013, 71, 37-41 Jawad, L. A.: Otolith mass asymmetry in Carangoides caeruleopinnatus

only 150 specimens ranging in total length between 202-313 mm were used in this work.

For the future studies, it is advisable to use large number of specimens and wide range of body size to further investigate the relationship between the otolith mass difference and the fish length.

acknowlEdGEmEnts I would like to thank the Ministry of Agriculture and Fisheries Wealth, the Agriculture and Fisheries Development Fund and the Marine Science and Fisheries Centre for giving us the opportunity to work on the fish samples within the qualitative and quantitative distribution of marine organisms in the Sultanate of Oman and for providing the appropriate financial support.

Sažetak asimEtrija masE otolita kod CarangoiDes CaerulepinnaTus (rÜppEll, 1830) (family: caranGidaE) iZ omanskoG mora Proučavana je asimetrija mase sagite kod vrste Carangoides caeruleopinnatus. Vrijednost asimetrije je računata kao razlika između mase desne i lijeve strane otolita dijeljena sa srednjom masom.

Rezultati pokazuju da apsolutna vrijednost za X kod C. caeruleopinnatus ne ovisi o dužini ribe i rastu otolita, kao što je to slučaj kod drugih simetričnih ribljih vrsta. Međutim, apsolutna vrijednost razlike mase otolita se povećava s dužinom ribe. Vrijednost x iznosi od -0,2 i +0,2.

Ključne riječi: otoliti, asimetrija mase, Carangoides caeruleopinnatus, Sultanat Oman

rEfErEncEs De Jong, H.A.A., Sondag, E.N.P.M., Kuipers, A., Oosterveld, W. J. (1996): Swimming behaviour of fish during short periods of weightlessness.

Aviatiation and Space Environmental Medicine.

67: 463-466.

Egorov, A.D., Samarin, G.I. (1970): Possible change in the paired operation of the vestibular apparatus during weightlessness. Kosmicheskaya biologiya I Aviakosmicheskaya Meditsina. 4: 85-86 (in Russian).

Hilbig, R., Anken, R.H., Bäuerle, A., Rahmann, H. (2002): Susceptibility to motion sickness in 40

fish: a parabolic aircraft flight study. Journal of Gravitational Physiology. 9: 29-30.

Hoffman, R.B., Salinas, G.A., Baky, A.A. (1977): Behavioural analyses of killifish exposed to weightlessness in the Apollo-Soyus Test Project.

Aviatiation and Space Environmental Medicine.

48: 712-717.

Jawad, L. A., Al-Mamry, J.M., Al-Busaidi, H.K. (2010): Otolith mass asymmetry in the teleost Beryx splendens Lowe, 1834 (Family: Bercidae) collected from the Arabian Sea coasts of Oman.

Thalassas. 26: 43-47 Jawad, L. A., Al-Mamry, J.M., Al-Mamari, H.M., Al-Yarubi, M.M., Al-Busaidi, H.K., AlMamary, D.S. (2011): Otolith mass asymmetry in Rhynchorhamphus georgi (Valenciennes, 1846)( Family: Hemiramphidae) collected from the Sea of Oman. J. Black Sea/Mediterranean Environment.17: 47- 55.

Lychakov, D.V. (1992): Morphometric studies of fish otoliths in relation to vestibular function. Zh. Evol. Biokhim. Fiziol. 28: 531-539 (in Russian).

Lychakov, D.V. (2002): Otolithic membrane: structural and functional organization, evolution, ecomorphological plasticity and tolerance to extreme conditions (Doctorskaya Dissertaziya), Vol 1. Sechenov Institute, St.-Petersberg (text, tables), pp. 1-266, Vol. 2 (illustrations), pp. 1-107 (in Russian).

Lychakov, D.V., Rebane, Y.T. (2004): Otolith mass asymmetry in 18 species of fish and pigeon. Journal of Gravitational Physiology. 11: 17-34.

Lychakov, D.V., Rebane, Y.T. (2005): Fish otolith mass asymmetry: morphometry and influence on acoustic functionality. Hearing Research. 201: 55-69.

Lychakov, D.V., Boyadzhieva-Mikhailova, A., Christov, I., Pashchinin, A.N., Evdokimov, I. I., Matkov, A.A. (1988): Changes in the otolith apparatus of rat and fish after prolonged exposure to acceleration. Kosmicheskaya biologiya I Aviakosmicheskaya Meditsina. 22: 27-33 (in Russian).

Lychakov, D.V., Rebane, Y.T., Lombarte, A., Fuiman, L.A., Takabayashi, A. (2006): Fish Otolith asymmetry: morphometry and modelling. Hearing Research. 219: 1-11.

Lychakov, D.V., Rebane, T.Y., Lombarte, A., Demestre, M., Fuiman, L. (2008): Saccular otolith mass asymmetry in adult flatfishes. Journal of Fish Biology. 72: 2579-2594.

Croatian Journal of Fisheries, 2013, 71, 37-41 Jawad, L. A.: Otolith mass asymmetry in Carangoides caeruleopinnatus

Rahman, H., Anken, R.H. (2002): Gravitational biology using fish as model systems for understanding motion sickness susceptibility. Journal of Gravitational Physiology. 9: 19-20.

Samarin, G.I. (1992): Study of the labyrinth asymmetry and its possible role in the motion sickness genesis (Tezisy Kandidatskoi Dissertazii).

Institute for Biomedical Problems, Moscow, pp.

1-33 (in Russian).

Scherer, H., Helling, K., Clarke, A.H., Hausmann, S. (2001): Motion sickness and otolith asymmetry.

Biological Science of Space. 15: 401-404.

Takabayashi, A. (2003): Functional asymmetry estimated by measurements of otolith in fish.

Biological Science of Space. 17: 293-297.

Von Baumgarten, R.J., Wetzig, J., Vogel, H., Kass, J.R. (1982): Static and dynamic mechanisms of space vestibular malaise. Physiologist. 25: 33-36.

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ii mEĐunarodni simpoZij o rodu HuCHo u poljskoj U mjestu Łopuszna u južnoj Poljskoj od 19. do 22. rujna održan je II Međunarodni simpozij o vrstama roda Hucho (II International Hucho Symposium), gdje pripada i naša mladica ili glavatica (Hucho hucho). Vrste ovoga roda spadaju u najveće pastrvske (salmonidne) ribe, te su stoga ugrožene u većem dijelu svoga areala. Na skupu je sudjelovalo pedesetak znanstvenika iz Europe, Azije i Sjeverne Amerike (sl. 1), a među njima i Tomislav Treer s Agronomskog fakulteta Sveučilišta u Zagrebu s pozvanim predavanjem pod naslovom „Huchen (Hucho hucho) in Croatia - past and present”. Osim o našoj europskoj glavatici dosta radova bilo je i o azijskoj vrsti Hucho taimen, a manje o drugim vrstama roda Hucho, te o rodu Parahucho. Posebno zanimljiva je bila prezentacija kolege Manu Esteve iz Španjolske (sl. 2). Prikazao je svoja istraživanja po cijelome svijetu gdje, unatoč fizičkom hendikepu, uronjen u potoke snima načine mrijesta pojedinih salmonidnih vrsta riba. Na taj način je zaključio da je izvorno ponašanje matica ovih riba nakon mrije-

Sl. 1: Sudionici simpozija Fig. 1: Participants of the symposium 42

sta u umjereno brzim tekućicama odmor. Vrste koje su se kasnije prilagodile mrijestu u brzim potocima moraju odmah šljunkom prekrivati ikru, kako je voda ne bi odnijela. Za razliku od njih, vrste koje su se prilagodile mrijestu u jezerima moraju repom mahati nad ikrom, kako bi ona dobila dovoljno kisika.

Zaključci skupa sažeti su u devet točaka. Iz njih se vidi da je ugroženost vrsta ovih rodova različitog stupnja. Dok je za dalekoistočne vrste dovoljna zaštita u vodama koje obitavaju, za našu glavaticu je potrebno uložiti i napore za njezinu reintrodukciju u niz voda. Pri tome treba voditi računa o genetskim razlikama među potpopulacijama, te nasađivati samo one autohtone. Stoga je nužno provesti genetsku analizu matica u svim mrjestilištima ovih riba. Uz to je nužno provesti i daljnja biološka istraživanja (mikrostaništa, telemetrija), kako bi se moglo ispravno gospodariti s njihovim stokovima.

Ovakvi podaci posebno nedostaju za neke dalekoistočne vrste, koje žive na ograničenom prostoru (H.

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Sl. 2: Zanimljivo izlaganje španjolskog znanstvenika Manu Esteve Fig. 2: Interesting presentation of Spanish scientist Manu Esteve

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Sl. 3: Na uzgajalištu glavatica (Hucho hucho) u mjestu Łopuszna s agilnim i slikovitim organizatorom skupa Andrzejem Witkowskim Fig. 3: At the huchen (Hucho hucho) farm in Łopuszna with agile and scenic organizer Andrzej Witkowski bleekeri i H. ishikawae). I za našu glavaticu podaci su oskudni, sigurno i zato što je teško doći do dovoljno primjeraka za analizu.

U susjedstvu hotela u kojem su sudionici bili smješteni nalazi se ribogojstvo koje se bavi mrješćenjem i uzgojem glavatice (sl. 3). Takva svoja isku-

stva na Kupi i dobru suradnju s članovima ribičkog društva s hrvatske strane iznio je i kolega Miha Ivanc iz Slovenije (treći slijeva na sl. 1). Očito je da će ovakvu suradnju trebati i dalje razvijati i proširivati, kako bi ova kraljica naših salmonidnih voda i dalje u njima uspješno plivala.

Prof. dr. sc. Tomislav Treer

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review article Dulčić, J., Đođo, Ž., Dragičević, B., Ćukteraš, M. NEW SPECIES IN THE ADRIATIC ICHTHYOFAUNA AND SOCIO-ECONOMIC CONSEQUENCES FOR CROATIAN MARINE FISHERIES

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review article Župan, I., Peharda, M., Bavčević, L., Šarić, T., Kanski, D. POTENTIAL FOR DEVELOPMENT OF INTEGRATED MULTI-TROPHIC AQUACULTURE (IMTA) IN THE ADRIATIC SEA S125

supplement to fishing profession Pažur, K. PROBLEMS WITH CORMORANTS ON CROATIAN WATERS

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croatian journal of fisHEriEs sadrŽaj, sijEčanj – prosinac 2012. (70) izvorni znanstveni članak Jelić, D. NOVI PODACI O DISTRIBUCIJI Cottus gobio (SCORPENIFORMES; COTTIDAE) U HRVATSKOJ S POSEBNIM OSVRTOM NA JADRANSKI SLIV

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izvorni znanstveni članak Jelkić, D., Opačak, A., Stević, I., Ozimec, S., Jug Dujaković, J., Safner, R. UZGOJ LIČINKI ŠARANA (Cyprinus Carpio) U RECIRKULACIJSKOM SUSTAVU (RAS)

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izvorni znanstveni članak Čikeš Keč, V., Zorica, B. MEZENTERIČNA MASNOĆA I KONDICIJA LOKARDE sComber Colias U JADRANSKOM MORU 19/1 pregledni članak Antolović, M., Antolović, N. BIOLOŠKE I EKOLOŠKE KARAKTERISTIKE MALE KAPICE Chlamys varia (LINNAEUS, 1758.) - OSNOVA KONTROLIRANOG UZGOJA 31/1 izvorni znanstveni članak Skejić, S., Marasović, I., Ninčević Gladan, Ž.

FITOPLANKTONSKI SASTAV NA UZGAJALIŠTU RIBA U UVALI MASLINOVA (OTOK BRAČ)

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izvorni znanstveni članak Zorica, B., Čikeš Keč, V. PRELIMINARNA ISTRAŽIVANJA O ISHRANI IGLICE belone belone (L., 1761) U JADRANSKOM MORU 53/2 kratko priopćenje Tomljanović, T., Treer, T., Aničić, I., Safner, R., Šprem, N. UGROŽENE RIBE SVIJETA: salmo obtusirostris salonitana (KARAMAN, 1926) (SALMONIDAE)

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kratko priopćenje Jawad, L. A., AL-Mamry, J. M DEFORMACIJA KAUDALNE PERAJE DUGOPERAJNOG CIPLA, moolgarda pedaraki (VALENCIEENES, 1836) (PISCES: MUGILLIDAE).

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pregledni članak Župan, I., Peharda, M., Ezgeta-Balić , D., Šarić, T. KUNJKA (ARCA NOAE LINNAEUS, 1758) – ŠTO MORAMO ZNATI PRIJE UVOĐENJA OVE VRSTE U AKVAKULTURU?

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izvorni znanstveni članak Tave, D., Valenzuela, L., Toya, L., M. Hutson, A. NOVI DIZAJN ZRAČNE PUMPE KOJA SE KORISTI U SPREMNICIMA ZA UZGOJ RIBE KOD UGROŽENE SREBRNE BJELICE IZ RIJEKE RIO GRANDE (hybognathus amarus)

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izvorni znanstveni članak Cotter, P. A., McLean, E., R. Craig, S., Craig, J., Westerman, M. CIJEPLJENJE HIBRIDNOG LUBINA: RAST, IMUNOLOŠKA REAKCIJA I EKSPRESIJA GENA

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izvorni znanstveni članak Sulić Šprem, J., Kožul, V., Antolović, N., Glavić, N., Bartulović, V. KVANTITATIVNO – KVALITATIVNI SASTAV ZAJEDNICA NEDORASLIH RIBA NA PODRUČJU UŠĆA NERETVE I MALE NERETVE U LJETNO-JESENSKOM RAZDOBLJU

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kratko priopćenje Jawad, L., Al-Mamry, J., Al-Mamari, D. FLUKTUACIJA ASIMETRIJE ŠIRINE OTOLITA KOD Carangoides Caeruleopinnatus (CARANGIDAE) ULOVLJENIH NA OBALI MUSCATA U OMANSKOM MORU

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kratko priopćenje Jawad, L. A., Al-Mamry, J. DEFORMACIJA LEĐNE PERAJE KOD SREBRNE PLOTICE, pampus argenteus (EUPHRASEN, 1788) (PORODICA: STROMATIDAE) NA OMANSKOJ OBALI ARAPSKOG ZALJEVA

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kratko priopćenje Piria, M., Treer, T., Ivanković, P., Tomljanović, T., Aničić, I., Safner, R., Matulić, D., Šprem, N. UGROŽENE RIBE SVIJETA: squalius svallize (HECKEL & KNER, 1858) (CYPRINIDAE)

prilozi ribarstvenoj struci Treer, T. 6. SVJETSKI RIBARSKI KONGRES

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izvorni znanstveni članak Jelić, M., Jelić, D., Žutinić , P., Ćaleta, M. ZNAČAJKE FAUNE RIBA DONJEG TOKA RIJEKE DRAVE I OKOLNIH POPLAVNIH STANIŠTA KOD DONJEG MIHOLJCA (ISTOČNA HRVATSKA) 153/4 izvorni znanstveni članak Tutman, P., Glamuzina, B., Dulčić, J., Zovko, N. IHTIOFAUNA MOČVARE HUTOVO BLATO (DONJI TOK RIJEKE NERETVE, BOSNA I HERCEGOVINA); STANJE I UGROŽENOST

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izvorni znanstveni članak Rajput, V. TOKSIČNO DJELOVANJE PESTICIDA KOJIMA JE ISTEKAO ROK TRAJANJA NA VRSTU Catla Catla IZ RIJEKE GAULI U INDIJI

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pregledni članak Đula, I., Slišković, M., Jelić Mrčelić, G. SISTEM DINAMIČKI MODEL PONAŠANJA OTPADA IZ MARIKULTURE

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pregledni članak Jelić Mrčelić, G., Slišković, M., Alaburić, T. UTJECAJ RIBOLOVA NA POPULACIJE DEMERZALNIH VRSTA RIBA - DVIJE STUDIJE SLUČAJA

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pregledni članak Pavić, V., Galović, D., Has-Schön, E., Bogut, I. KONTROLA RASTA ALGI U VODNIM EKOSUSTAVIMA UPOTREBOM SLAME JEČMA

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prilozi ribarstvenoj struci Treer, T. 14. EUROPSKI IHTIOLOŠKI KONGRES izvorni znanstveni članak Mustać, B., Sinovčić, G. EKSPLOATACIJA I SMRTNOST SRDELE GOLEME sardinella aurita, VALENCIENNES, 1847. U ISTOČNOM DIJELU SREDNJEG JADRANA

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izvorni znanstveni članak Tutman, P., Ćaleta, M., Glamuzina, B., Dulčić, J. BIOLOŠKO-EKOLOŠKE OSOBITOSTI, RASPROSTRANJENOST I STANJE ZAŠTITE PEŠKELJA, sCardinius plotizza (HECKEL I KNER, 1858) (PISCES, CYPRINIDAE) NA PODRUČJU MOČVARE HUTOVO BLATO U BOSNI I HERCEGOVINI S15 izvorni znanstveni članak Kapetanović, D., Dragun, Z., Valić, D., Vardić Smrzlić, I., Teskeredžić, Z., Teskeredžić, E. ODREĐIVANJE BROJA HETEROTROFNIH BAKTERIJA U JADRANSKIM UZGAJALIŠTIMA PRIMJENOM RAZLIČITIH METODA

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izvorni znanstveni članak Matić-Skoko, S., Stagličić, N., Pallaoro, A., Vrbatović, A., Bušelić, I. ZDRAVI PRISTUP ZDRAVOJ HRANI IZ ZDRAVOG MORA: VALORIZIRANJE RIBE KOJA POTJEČE IZ ZAŠTIĆENOG PODRUČJA

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prethodno priopćenje Agić, B., Zubak, I., Kruschel, C., T. Schultz, S., Blindow , I. ODREĐIVANJE BROJNOSTI PREDATORA KORIŠTENJEM EKSPERIMENTALNOG RIBOLOVA: USPOREDBE UNUTAR I IZVAN MORSKIH ZAŠTIĆENIH PODRUČJA U SREDNJEM JADRANU

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prethodno priopćenje Kruschel, C., T. Schultz, S., Bakran-Petricioli, T., Petricioli, D. USPOREDBA BROJNOSTI PREDATORA I RAZNOLIKOSTI RIBA U ZAŠTIĆENIM PODRUČJIMA (NP KORNATI, HRVATSKA) I SUSJEDNIM PODRUČJIMA U KOJIMA JE DOZVOLJEN RIBOLOV S65 prethodno priopćenje Ćirković , M., Ljubojević, D., Župan, B., Bogut, I., Đorđević, V., Novakov, N., Matekalo-Sverak, V. USPOREDNI PRIKAZ KVALITETE MESA NEKIH VRSTA RIBA IZ PORODICE ŠARANKI U REPUBLICI SRBIJI

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prethodno priopćenje Ljubojević, D., Ćirković , M., Babić, J., Novakov, N., Marković, T. UTJECAJ RAZLIČITIH ČIMBENIKA NA RANDMAN KOMERCIJALNO UZGAJANIH CIPRINIDNIH VRSTA RIBA NA ŠARANSKIM RIBNJACIMA U SRBIJI

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pregledni članak Lujić, J., Kostić, D., Popović, E., Ćirković , M., Ljubojević, D., Novakov, N., Marinović, Z. PRISUTNOST NAJVAŽNIJIH GOSPODARSKI ZNAČAJNIH VRSTA RIBA U DUNAVU I NJEGOVIM POPLAVNIM ZONAMA U SRBIJI

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pregledni članak Dulčić, J., Đođo, Ž., Dragičević, B., Ćukteraš, M. NOVE VRSTE U JADRANSKOJ IHTIOFAUNI I SOCIO-EKONOMSKE POSLJEDICE NA HRVATSKO MORSKO RIBARSTVO

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pregledni članak Župan, I., Peharda, M., Bavčević, L., Šarić, T., Kanski, D. MOGUĆNOSTI RAZVOJA INTEGRIRANE MULTI-TROFIČKE AKVAKULTURE NA JADRANU

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prilozi ribarstvenoj struci Pažur, K. PROBLEMI S KORMORANIMA NA HRVATSKIM VODAMA

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fisHEriEs rElatEd confErEncEs may 2013 UK & IRELAND NEW 9 May 2013 Improving Coarse Fish Stocks in Rivers Conference Barston Lakes, Solihull, England Website: http://www.theriverstrust.org/events/ coarse_conference/index.html 22-23 May 2013 Impacts of Noise and Vibration on Fish Conference Kenwood Hall, Sheffield, England Website: http://www.ifm.org.uk Contact: paul.coulson@ifm.org.uk Date correction 25-27 June 2013 IFM European Eel Conference: Breaking Down Barriers Fishmongers Hall, London, England Website: http://www.ifm.org.uk Contact: paul.coulson@ifm.org.uk 8-11 July 2013 Annual Symposium of the Fisheries Society of the British Isles: Deep-Sea Fish Biology University of Glasgow, Scotland Website: http://www.fsbi.org.uk 22-24 October 2013 Institute of Fisheries Management Annual Conference – What have fish ever done for us? – The importance of good fisheries management in modern society City Hall, Cardiff, Wales Website: http://www.ifm.org.uk Contact: paul.coulson@ifm.org.uk NEW 27-28 November 2013 IBIS & Atlantic Salmon Trust Conference – Boosting salmon numbers: is stocking the answer or the problem?

Marriott Hotel, Glasgow, Scotland Website: http://www.loughs-agency.org/ibis/ibisevents/salmon-stockiing-conference/

3-7 August 2014 ICBF2014: 11th International Congress on the Biology of Fish Edinburgh, Scotland Website: http://www.icbf2014.sls.hw.ac.uk/

EUROPE 1-5 July 2013 Symposium for European Freshwater Sciences Münster, Germany Website: http://www.sefs2013.de/?node=14 9-12 August 2013 Aquaculture Europe 2013 Trondheim, Norway Website: http://www.marevent.com/ AE13Trondheim.html 2-6 September 2013 16th International Conference on Diseases and Shellfish Tampere, Finland Website: http://eafp.org/tampere/ 11-13 September 2013 European River Restoration Conference: Celebrating Successes and Addressing Challenges Vienna, Austria Website: http://www.errconference.eu/ 23-24 September 2013 Aquaculture Forum Bremerhaven 2012-2013: Developmental trends and diversification in European aquaculture Bremerhaven, Germany Contact: grabs@bis-bremerhaven.de 3-7 November 2013 Aquaculture 2013: To the next 40 years of sustainable global aquaculture Las Palmas, Gran Canaria, Spain Website: http://www.aquaculture-conference.com

September 2014 Fish and Ecological Quality of Lakes and Reservoirs - Preliminary announcement of conference to be organized by Biology Centre of the Academy of Sciences Czech Republic Contact: x.fenix@seznam.cz NEW 10-13 October 2013 15th Panhellenic Congress of Ichthyologists Thessaloniki, Greece Website: http://www.psid.gr/index. php?option=com_content&view=category&layout= blog&id=9&Itemid=16

REST OF WORLD NEW 30 May- 1 June FABA 2013 Symposium – Fisheries and Aquatic Sciences Ezurum, Turkey Website: http://www.faba2013.com/ 2-6 June 2013 37th Annual Larval Fish Conference Miami, Florida, USA Website: http://www.larvalfishcon.org/ 25-27 June 2013 Engineering and Ecohydrology for fish passage Oregon State University, Corvallis, Oregon, USA Website: http://fishpassage.umass.edu/ 24-28 June 2013 9th Indo-Pacific Fish Conference Okinawa, Japan Website: http:/www.fish-isj.jp/9ipfc/

21-25 July 2013 7th International Symposium on Sturgeon (ISS7) Nanaimo, British Columbia, Canada Website: http://iss7.viu.ca/ 9-11 August 2013 Ornamental Fish Health Symposium University of New England, Maine, USA Website: http://www.neaquatech.org/ uneconference/ 18-22 August 2013 Australian Society for Fish Biology Conference – Aquatic science at the interface University of Waikato, Hamilton, New Zealand Website: http://www.asfb.org.au/events/ 8-12 September 2013 American Fisheries Society Annual meeting – Preparing for challenges ahead Little Rock, Arkansas, USA Website: http://afs2013.com/ 18-20 September 2013 Fifth International Conference of the PanAfrican Fish and Fisheries Association Bujumbura, Burundi Website: http://africhthy.org/content/2013-paffaconference-2013-conf%C3%A9rence-paffa NEW 3-5 January 2014 67th Canadian Conference for Fisheries Research Yellowknife, NWT, Canada Website: http://www.uwindsor.ca/glier/ccffr/ 17-21 August 2014 38th Annual Larval Fish Conference Quebec City, Quebec, Canada Website: http://www.larvalfishcon.org/

14-19 July 2013 2nd International Conference on Fish Telemetry Grahamstown, South Africa Website: http://www.2ndicft.co.za/

Updated website 1-4 September 2014 7th World Recreational Fishing Conference Campinas, State of Sao Paulo, Brazil Website: http://www.7wrfc.com/

17-19 July 2013 World conference on stock assessment methods Boston, USA Website: http://www.ices.dk/iceswork/symposia/ wcsam.asp

7-11 November 2016 (proposed dates) 7th World Fisheries Congress Busan, Korea Website: TBA