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Suffolk Natural History, Vol. 46 BLACKFISH CENTROLOPHUS NIGER (CENTROLOPHIDAE) OFF THE SUFFOLK COAST J. R. ELLIS
Blackfish, barrelfish and medusa fish (Order Perciformes; Suborder Stromateoidei; Family Centrolophidae) are a group of epipelagic and mesopelagic fish that are generally found in warm and temperate oceanic waters (Haedrich, 1986). The family contains seven genera and about 28 species (Nelson, 2006). Three species have been reported from UK waters, namely the blackfish Centrolophus niger (Gmelin, 1788), barrelfish Hyperoglyphe perciformis (Mitchill, 1818) and Cornish blackfish Schedophilus medusophagus Cocco, 1839 (Wheeler et al., 2004). A fourth species, imperial blackfish Schedophilus ovalis (Cuvier, 1833) also occurs in European Atlantic waters (Haedrich, 1986), and has also been reported recently from off Ireland (see Wheeler et al., 2004). C. niger is distinguished from the other centrolophids in UK waters by having weakly developed spines in the dorsal fin (c.f. H. perciformis, which has 5–9 robust spines in the dorsal fin), and that the pre-opercular margin only has weak denticulation (c.f. Schedophilus spp., in which the pre-opercular margin has 9–15 small spines). Additionally, C. niger has a relatively elongated body, a single dorsal fin of which the origin is posterior to the base of the pectoral fin, and small teeth on the jaws only (with no teeth on the tongue or on the roof of the mouth). C. niger is black-brown in colour and can attain a length of >1·5 m. C. niger is considered to be an uncommon species that occurs off the continental slope in waters of 100–600 m depth (Wheeler et al., 2004), although occasional vagrants have been recorded from the coastal waters of Britain. With regards the occurrences of this species in shallower waters, Wheeler (1978) commented “Whether this is due to migration by the fishes, or to movements of water masses in which they are living, is not known”. Little is known about the biology of these species, due to their offshore distributions, although C. niger is reported to feed on small fish, cephalopods, deep-water medusae and planktonic crustaceans (Haedrich, 1986; Wheeler et al., 2004). Although neither Patterson (1910) nor Collings (1933) included C. niger in their list of the fishes of Suffolk, Patterson (1905) previously reported on a specimen that was washed ashore at Sea Palling in Norfolk during March 1898, and Laver (1898) reported on one specimen (as Centrolophus pompilus) from outside the River Colne in Essex. Although there are few records of C. niger in the southern North Sea (Table 1), this note documents three recent captures of blackfish off the Suffolk coast. The first specimen (51 cm, 994 g) was caught off Minsmere in early November 2009, the second specimen (60 cm, 1,949 g) was caught off Sizewell in April 2010 (Plate 5), and a third specimen was caught off Felixstowe Ferry in late June 2010 (59 cm, 1,973 g). An overview of the available records of blackfish caught in the southern and central North Sea indicates that blackfish may be captured occasionally throughout the year, although most specimens are reported between October and April. The individuals caught are typically across the length range 41–65 cm in length (Table 1).
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Table 1: Records of blackfish Centrolophus niger in the North Sea Date
Location
Size
Source
Sep 1955 Nov 1957 Feb 1958
Turbot Bank Moray Firth East from Aberdeen Wee Bankie (Firth of Forth) Silver Pits Clay Deep (55°N 4°E) 52°24’N, 04°32’E North of Terschelling 54°19’, 00°53’E Ling Bank 12 miles east of Fetlar 52°45’N, 02°30’E Felixstowe 11km north-east of Hartlepool Harwich Newbiggin by Sea Newbiggin by Sea North of Dogger bank Sizewell off Minsmere Sizewell Felixstowe Ferry
-
Rae and Wilson (1957)* Rae and Lamont (1959)* Rae and Lamont (1960)*
-
Rae and Lamont (1961)*
56 cm 52 cm
Blacker (1967) Blacker (1969)
41 cm -
De Groot (1974) De Groot (1976)
51 cm 45 cm 57 cm
Blacker (1981) Shelton (1983)* Shelton (1983)*
55 cm 52 cm 63 cm
De Groot (1985) Millner (1986a) Millner (1986b)
Jul 1959 Aug 1965 Dec 1968 Apr 1972 Nov 1976 Aug 1979 Mar 1980 Dec 1980 Nov 1982 Jan 1983 Feb 1984 Apr 1988 Oct 1989 Dec 1991 Jan 1992 Oct 1992 Nov 2009 Apr 2010 Jun 2010
50 cm (1,200 g) Cefas (unpubl. data) 50 cm (1,080 g) Cefas (unpubl. data) 55 cm Cefas (unpubl. data) 65 cm 51 cm (994 g) 60 cm (1,949 g) 59 cm (1,973 g)
Cefas (unpubl. data) Cefas (unpubl. Data) This study This study This study
*Scottish records of blackfish from around the west coast of the Shetland Isles are not summarised here. Coincidentally, several Ray’s bream Brama brama, another oceanic fish more commonly encountered from the west of the British Isles, were reported from various beaches in Norfolk in the winter of 2009. There are periodic incursions of Ray’s bream into the North Sea, with dead or moribund specimens subsequently found stranded on the eastern coasts of England in the winter, possibly due to the decreasing sea temperature (Wheeler and Blacker, 1969). The occurrence of oceanic fish, such as blackfish and Ray’s bream, in
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the southern and central North Sea may be related to incursions of oceanic water into the North Sea basin. Although the factors that influence such inflows of Atlantic water are poorly understood, there have been reports of other oceanic species occurring following such events (e.g. Edwards et al., 1999; Reid et al., 2001). Acknowledgements Thanks to the local fishing skippers who provided the specimens of blackfish, and Peter Walker for the unpublished records of blackfish. References Blacker, R. W. (1967). English observations on rare fish in 1965. Annales Biologiques, Copenhagen 22: 186–187. Blacker, R. W. (1969). English observations on rare fish in 1968. Annales Biologiques, Copenhagen 25: 257–259. Blacker, R. W. (1981). English observations on rare fish in 1979. Annales Biologiques, Copenhagen 36: 195–196. Collings, D. W. (1933). The fishes of Suffolk. Transactions of the Suffolk Naturalists’ Society 2: 104–133. De Groot, S. J. (1974). Dutch observations on rare fish in 1972. Annales Biologiques, Copenhagen 29: 181–182. De Groot, S. J. (1976). Dutch observations on rare fish in 1976. Annales Biologiques, Copenhagen 33: 184. De Groot, S. J. (1985). Dutch observations on rare fish in 1982. Annales Biologiques, Copenhagen 39: 186–187. Edwards, M., John, A. W. G., Hunt, H. G. and Lindley, J. A. (1999). Exceptional influx of oceanic species into the North Sea in late 1997. Journal of the Marine Biological Association of the United Kingdom 79: 737–739. Haedrich, R. L. (1986). Centrolophidae. In Fishes of the North-Eastern Atlantic and the Mediterranean (Whitehead, P. J. P., Bauchot, M.-L., Hureau J.-C., Nielsen J., and Tortonese E., eds.). Volume III. UNESCO, Paris, 1177–1182. Laver, H. (1898). The mammals, reptiles and fishes of Essex. Essex Field Club Special Memoirs, Volume III, 138 pp. Millner, R. S. (1986a). English observations on rare fish in 1983. Annales Biologiques, Copenhagen 40: 188. Millner, R. S. (1986b). English observations on rare fish in 1984. Annales Biologiques, Copenhagen 41: 162–163 Nelson, J. S. (2006). Fishes of the world. Fourth edition. John Wiley & Sons, New Jersey, 601 pp. Patterson, A. H. (1905). Nature in eastern Norfolk. Methuen & Co., London Patterson, A. H. (1910). Rough notes on the fish and fisheries of East Suffolk. John Buckle, Great Yarmouth, 55pp. Rae, B. B. and Lamont, J. M. (1959). Rare fishes: Scotland. Annales Biologiques, Copenhagen 14: 85–86. Rae, B. B. and Lamont, J. M. (1960). Rare fishes: Scotland. Annales Biologiques, Copenhagen 15: 78.
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Rae, B. B. and Lamont, J. M. (1961). Rare fishes: Scotland. Annales Biologiques, Copenhagen 16: 104–105. Rae, B. B. and Wilson, E. (1957). Rare fishes: Scotland. Annales Biologiques, Copenhagen 12: 103. Reid, P. C. Holliday, N. P. and Smyth, T. J. (2001). Pulses in the eastern margin current and warmer water off the north west European shelf linked to North Sea ecosystem changes. Marine Ecology Progress Series 215: 283–287. Shelton, R. G. J. (1983). Scottish observations on rare fish in 1980. Annales Biologiques, Copenhagen 37: 235. Wheeler, A. (1978). Key to the fishes of northern Europe. Frederick Warne, London, 380 pp. Wheeler, A. and Blacker, R. W. (1969). Rare and little-known fishes in British Seas in 1966 and 1967. Journal of Fish Biology 1: 31–331. Wheeler, A. C., Merrett, N. R. and Quigley, D. T. G. (2004). Additional records and notes for Wheeler’s (1992) list of the common and scientific names of fishes of the British Isles. Journal of Fish Biology 65 (Supplement B): 40 pp.
J. R. Ellis
Jim Ellis CEFAS Lowestoft Laboratory Pakefield Road Lowestoft Suffolk NR33 0HT
Plate 5: Blackfish, Centrolophus niger (Gmelin), caught off Sizewell (p. 6).
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