The non-marine Mollusca of Suffolk by Suffolk Naturalists' Society

THE NON-MARINE MOLLUSCA OF SUFFOLK I. J. KILLEEN

The interest in the non-marine Mollusca of Suffolk has a history going back to the early nineteenth Century. In 1823 Revett Sheppard, a local parson, published an account of land and freshwater shells including a list of Suffolk species. There followed a gap until 1891 when C. Greene published a catalogue of the Land and Freshwater Shells of Suffolk. In the ensuing years several accounts on Suffolk Mollusca by Arthur Mayfield appeared in the Journal of Conchology. Continued interest by local naturalists, notably G. T. Rope, C. Morley and C. G. Doughty culminated in a summary of the Mollusca of Suffolk by Morley in 1938. Apart from a few short notes in these Transactions very little work was carried out in the county for the next 30 years. In 1961 the Conchological Society of Great Britain and Ireland instigated a national survey based on the 10km grid squares of the Ordnance Survey. So far as Suffolk was concerned, the vast bulk of the recording for this project was carried out between 1967 and 1974 by visiting members of the Society with some assistance from local naturalists. The results of this survey were published as an Atlas of the Non-Marine Mollusca of the British Isles (Kerney, 1976a). Recording has continued Over the last 10 years and a second edition of the Atlas is planned for the near future. Several interesting distribution patterns emerged from this survey, reflecting physical effects such as geology and climate. However, at county or vice-county levels, the 10km Square is a rather coarse mapping unit. It has become usual for the 2 X 2km Square, or tetrad, to be used as the unit for recording at county level. This enables a more precise method of showing the distribution of a species within a given area. Several tetrad atlases have already been produced in many counties, particularly for flora but also other groups, e.g. The Non-Marine Mollusca of the Isle of Wight (Preece, 1980) and most recently for Butterflies in our own county (Mendel & Piotrowski, 1986). In 19801 embarked on a survey to record the mon-marine Mollusca of the county, i.e. East Suffolk (v.c. 25) and West Suffolk (v.c. 26), using the tetrad grid system. To date (January 1986) some 600 tetrads have been investigated. The attached map shows the coverage and number of species from each tetrad. Even with 60% coverage many distinct distribution patterns are emerging. Furthermore, incorporation of old records has revealed that many species are declining or are on the verge of extinction in Suffolk. A major factor responsible for these declines is the loss of habitats such as rieh wetlands and chalk grassland. DĂźring the course of the present survey several species previously unrecorded in v.c. 25 and 26 have been discovered:

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East Suffolk - v. c. 25 Marstoniopsis scholtzi (Schmidt) - May 1981, River Deben, Rendlesham. (TM 322534) Physa acuta (Draparnaud) - June 1981, stream, Langer Park, Felixstowe. (TM 294348) Milax gagates (Ferussac) - June 1981, garden, Kesgrave. (TM 233459) Deroceras caruanae (Pollonera) - March 1982, garden, Levington. (TM 233396) West Suffolk-v.c. 26 Milax gagates (Ferussac) - June 1982, hedgebanks, Old Newton. (TM 043623) Boettgerilla pallens (Simroth) - May 1984, Ickworth Park. (TL 813620) Deroceras caruanae (Pollonera) - March 1985, Great Cornard. (TL 886399) Pisidium moitessierianum Melford. (TL 856436)

Paladilhe - March 1981, River Stour, Long

In addition, the following recently segregated species have been verified: Columella aspera Waiden (v.c. 25 and 26) Arion distinctus Mabille (v.c. 25 and 26) Euconulus alderi (Gray) (v.c. 25 and 26) The main aim of this account is to review the progress of the present survey. It is estimated that another two or three years field work is required before the results can be published as an Atlas of the Non-Marine Mollusca of Suffolk. However, apart from the data in the Vice-Comital Census (latest edition Kerney, 1982), it is almost 50 years since Morley published the last fĂźll list of the county's Mollusca. Many species have been added since then, some probably overlooked, some are recent arrivals and others are recent segregates. The following list includes all species recorded living from the county, as well as recent extinctions, but excludes those known only as Flandrian fossils. The taxonomic arrangement essentially follows that of the Atlas of the Non-Marine Mollusca ofthe British Isles (Kerney, 1976a) which employs the nomenclature of Waiden (1976) and Kerney (1976b) for the land and freshwater mollusca respectively. A brief description of the status and distribution of each species is included. Only Latin names are used for the species in the list. Common or English names do not exist for the majority of species, and those that do are often

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THE NON-MARINE MOLLUSCA OF SUFFOLK

used for more than one species. Use of trivial names for non-marine Mollusca can only lead to confusion and, therefore, is best discouraged. * Species not recorded by Morley Theodoxus fluviatilis (L.). R. Stour, R. Waveney, Single records from the Brett and Gipping. Viviparus contectus Millet. R. Stour, Waveney, Little Ouse and Latymere Dam. Infrequent in the R. Lark and Black Bourn. Drains at Eastbridge. Viviparus viviparus (L.). Restricted to the R. Waveney below Bungay. Valvata cristata Müller. Common in rivers, drains, ponds and ditches throughout. Valvata macrostoma Mörch. Old records from Brandon. Possibly extinct. Valvatapiscinalis

(Müller). Common in all the rivers.

Pornatias elegans (Müller). A colony at Little Blakenham is the only post 1970 record. A declining species in Suffolk. Hydrobia ventrosa (Montagu). Brackish lagoons from the Stour to Breydon Water. * Hydrobia neglecta Muus. First recorded in Suffolk at Aldeburgh in 1976. Two further records at Walberswick. Hydrobia ulvae (Pennant). Abundant in most saltmarsh habitats. Pseudamnicola confusa (Frauenfeld). Abundant at Oulton Broad. Further records from the R. Waveney where there is a slight brackish influence. Potamopyrgus jenkinsi (Smith). Rivers, streams, etc. Abundant in the south of the county. Less frequent but widely distributed elsewhere. * Marstoniopsis scholtzi (Schmidt). Very rare, a few shells discovered at two sites on the R. Deben between Ufford and Wickham Market. Possibly overlooked due to its similarity to Potamopyrgus jenkinsi. Bithynia tentaculata (L.). Common and widely distributed in rivers, ponds, drains, etc. Bithynia leachii (Sheppard). Widespread but more local than B. tentaculata. Sheppard's description of this species was based on shells from Holbrook millpond. Assimineagrayana Fleming. Locally common on saltmarshes from the Stour to Breydon Water. Acicula fusca (Montagu). Very rare, only two post 1980 records from Bealings and Otley. Carychium minimum Müller. Widespread and common in wet habitats. * Carychium tridentatum (Risso). Widespread and common in drier habitats than C. minimum.

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Ovatella myosotis (Draparnaud). Common in saltmarsh habitats. Leucophytia bidentata (Montagu). One record from Aldeburgh. Possibly under-recorded due to its cryptic habitat. Aplexa hypnorum where. Physafontinalis

(L.). Common in ditches in central Suffolk, rare else-

(L.). Common in all the rivers.

* Physa acuta (Draparnaud). An introduced species. Few records as yet from Felixstowe and the R. Stour near Haverhill. Will tolerate polluted water. Lymnaea truncatula (L.). Abundant throughout in streams, ditches, etc. Lymnaea glabra (Müller). Probably extinct, one old record from Beccles. Lymnaea palustris (L.). Widespread and common. Rivers, drains, etc. Lymnaea stagnalis (L.). Frequent in the main rivers. Lymnaea auricularia (L.). Frequent in the main rivers. Lymnaea peregra (L.). Abundant throughout in all freshwater habitats. Myxas glutinosa (Müller). Extinct. Old records from Needham Market and Mildenhall. Planorbisplanorbis Planorbis species.

(L.). Widespread, common. Rivers, drains, etc.

carinatus Müller. Widespread, less common than preceding

Anisus leucostoma (Millet). Abundant in suitable habitats (ditches). Anisus vortex (L.). Widespread and common. Rivers, ponds, drains, etc. Anisus vorticulus (Troschel). Rare, a few records from marsh drains around Barnby and Kessingland. Bathyomphalus

contortus (L.). Widespread, common.

* Gyraulus laevis (Alder). A thriving colony in a pond at Pettistree. One old record from Aldeburgh. Gyraulus albus (Müller). Widespread, common. Rivers, drains, etc. Armiger crista (L.). Frequent throughout. Mainly in ponds. Hippeutis complanatus (L.). Frequent throughout. Ponds, rivers, etc. Segmentina nitida (Müller). Last recorded in 1970, possibly extinct. Planorbarius corneus (L.). Locally common in the large rivers. Ancylus fluviatilis Müller. Very common in south-west Suffolk. Infrequent elsewhere. Prefers flowing water with a stoney bottom. Acroloxus lacustris (L.). Frequent, generally in the main rivers. Succineaputris

(L.). Widespread, frequent. Wetlands.

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Oxyloma pfeifferi habitats.

(Rossmässler). Common throughout in most damp

* Oxyloma sarsi (Esmark). Rare, marshes at Oulton Broad and lower Waveney Valley, dissection records only. Azecagoodalli (Ferussac). Frequent amongst moss on roadside banks in the centre of the county, rare elsewhere. Cochlicopa lubrica (Müller). Abundant throughout, catholic. * Cochlicopa lubricella (Porro). Widespread, more local than the preceding species, in drier habitats. Columella edentula (Draparnaud). Widespread but local. Damp woodlands, marshes, etc. * Columella aspera Waiden. Ten records, prefers much poorer, drier habitats than C. edentula. Truncatellina cylindrica (Ferussac). One very old record from Burgh Castle. Vertigo pusilla Müller. Rare, four records in the south-east, one in the north-west. Usually in dry habitats. Vertigo antivertigo (Draparnaud). Widespread, but very local. Many old records, declining. Hygrophillic. Vertigo substriata (Jeffreys). Rare, similar distribution to V. pusilla. Vertigo pygmaea (Draparnaud). Frequent throughout in open habitats. Vertigo moulinsiana (Dupuy). Rare, restricted to the marshes around Oulton Broad, and at Market Weston Fen. Vertigo angustior Jeffreys. Very rare, rediscovered living in Suffolk in 1982 at Martlesham (Killeen, 1983). Old records from Redgrave Fen and Aldeburgh. Pupilla muscorum (L.). Frequent in the west and a few coastal sites in south-east Suffolk in grassland habitats. Many old records. A declining species. Lauria cylindracea (da Costa). A curious distribution, common in northwest, south-east and east, virtually absent elsewhere. Woodland, hedgebanks, walls, etc. Vallonia costata (Müller). Common throughout, catholic. Vallonia pulchella (Müller). Widespread but local in wetland habitats. Vallonia excentrica Sterki. Widespread, common in grassland and open habitats. Acanthinula banks, etc.

aculeata (Müller). Frequent throughout, woodlands, hedge-

Ena montana (Draparnaud). Rare, restricted to a few sites in the south-west

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around Lavenham. A species on the north-east edge of its ränge in Britain. Ena obscura (Müller). Widespread, common. Punctum pygmaeum (Draparnaud). Common throughout. Probably underrecorded due to its minute size. Discus rotundatus (Müller). Abundant, catholic. Arion ater (L.) agg. Common throughout. *Arion subfuscus woods.

(Draparnaud). Widespread but very local, usually in

Arion circumscriptus Johnston. Common throughout. * Arion silvaticus Lohmander. Few records, possibly under-recorded due to confusion with the preceding species. * Arion fasciatus (Nilsson). Rare, four records in v.c. 26. Arion hortensis Ferussac and * Arion distinctus Mabille. It has been recently shown that Arion hortensis is an aggregate species (Davies, 1979). As such it is very common throughout the county. To date, nearly a hundred samples have been segregated revealing that Arion distinctus is by far the more common species. Arion intermedius Normand. Widespread, common. Vitrina pellucida (Müller). Very common throughout. Vitrea crystallina (Müller). Widespread, common in damp habitats. *Vitrea contracta (Westerlund). Widespread, in drier habitats than V. crystallina. Nesovitrea hammonis (Ström). Widespread, rarely common. Aegopinella pura (Alder). Widespread, locally common in woods, hedgebanks, etc. Aegopinella nitidula (Draparnaud). Abundant throughout. Oxychilus draparnaudi (Beck). Widespread, mainly in gardens. Oxychilus cellarius (Müller). Very common throughout. Catholic. Oxychilus alliarius (Miller). Widespread, common. Oxychilus helveticus (Blum). Abundant in west Suffolk, virtually absent from the east, thus apparently marking the limit of its ränge. Zonitoides nitidus (Müller). Widespread in wet habitats. [Zonitoides excavatus (Alder). One old, doubtful record from near Bury. Not accepted in the census.] Milax gagates (Draparnaud). Mainly confined to gardens in the south-east, virtually absent elsewhere. Trans. Suffolk Nat. Soc. 22

THE NON-MARINE MOLLUSCA OF SUFFOLK

Milax sowerbyi (Ferussac). Mainly confined to gardens in the south-east, possibly under-recorded through lack of garden records. * Milax budapestensis (Hazay). Widely distributed, infrequent. * Boettgerillapallens Simroth. Specimens discovered at Ickworth (v.c. 26) in 1984. A spreading species in Britain. Limax maximus L. Frequent throughout. Limax flavus L. Few records, certainly under-recorded due to its elusive nature. A synanthropic species (associated with man; gardens, urban habitats etc.) and usually nocturnal. Limax marginatus Müller. Widespread but local in old woodlands. Deroceras laeve (Müller). Widespread, common in wet habitats. Deroceras reticulatum species in Suffolk.

(Müller). Abundant everywhere, the commonest

* Deroceras caruanae (Pollonera). A recent arrival in Suffolk, widely distributed but uncommon, possibly under-recorded. * Euconulus alderi (Gray). Locally common in wet habitats, widespread. Euconulus fulvus (Müller). Widespread, common. Ceciliodes acicula (Müller). Frequent throughout. Cochlodina laminata (Montagu). Locally common from the south-west to north-east. Woodlands, hedgebanks, etc. Clausilia bidentata (Ström). Common throughout. Baleaperversa

(L.). Rare, only a few recent records.

Testacella haliotidea Draparnaud. Many old records, not found during the present survey. Testacella scutulum Sowerby. One old record from Campsey Ash. Due to confusion in the past many of the old records for the Testacella species are unreliable. It is likely that some of the T. haliotidea records are in fact T. scutulum. Candidula intersecta (Poiret). Widespread, common. * Candidula gigaxii (Pfeiffer). Widespread but local. Hedgebanks, grassland, etc. Cernuella virgata (da Costa). Common on chalk and along the south-east coast. Helicella itala (L.). Recent live records only from the extreme west of the county on chalky grassland. A declining species. Cochlicella acuta (Müller). A vagrant colony discovered at Newbourn in 1933.

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Monacha cartusiana (Müller). Recently recorded living at two sites near Alderton (v.c. 25): Apparently extinct atitsformer stations. Aspecieson the northern limit of its ränge in Britain. Monacha cantiana (Montagu). Widespread, very common. Ashfordia granulata (Alder). Widespread but very local. [Zenobiella subrufescens (Miller). Two old doubtful records from Cockfield and Felsham. Not accepted in the census.] Trichia striolata (Pfeiffer). Very common throughout. Trichia hispida (L.) and * Trichiaplebeia (Draparnaud). The high variability of these species renders identification difficult. T. hispida is very common throughout Suffolk whereas the T. plebeia form appears to occur mainly in the north and centre of the county. Arianta arbustorum (L.). Locally frequent in the east, very rare in the west. Damp woodlands, marshes, etc. Helicigona lapicida (L.). No live records since 1971, possibly extinct in Suffolk. Cepaea nemoralis (L.). Widespread, but most common in the north and north-west. Much less frequent than the following species. Cepaea hortensis (Müller). Very common throughout most of the county. Less frequent in the north-west where it is replaced by C. nemoralis. Helix aspersa Müller. Common throughout. Helix pomatia L. Two well established colonies at Little Blakenham (v.c. 25) and E of Long Melford (v.c. 26). Uniopictorum

(L.). Restricted to R. Waveney and R. Little Ouse.

Anodonta cygnea (L.). Mainly in the large rivers. Anodonta anatina (L.). In most rivers, apparently absent from the Gipping. * Pseudanodonta complanata (Rossmässler). Rare, R. Waveney only. Sphaerium corneum (L.). Common in all the rivers. Sphaerium lacustre (Müller). Widespread, rather uncommon. Pisidium amnicum (Müller). Frequent in the main rivers. Pisidium casertanum (Poli). Widespread, frequent. Pisidiumpersonatum

Malm. Abundant in ditches and streams.

Pisidium obtusale (Lamarck). Rather local in stagnant water. Pisidium milium Held. Common in rivers and streams. * Pisidium pseudosphaerium 25).

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Schiesch. Single record from Minsmere (v.c.

T H E N O N - M A R I N E MOLLUSCA OF SUFFOLK

Pisidium subtruncatum Malm. Common in rivers and streams. * Pisidium supinum Schmidt. R. Waveney and R. Little Ouse only. Pisidium henslowanum (Sheppard). Frequent in the main rivers. The type locality is Holbrook millpond (see also Bithynia leachii). Pisidium hibernicum Westerlund. Scarce, recorded from most of the main rivers. Pisidium nitidum Jenyns. Very common in streams and rivers. Pisidium pulchellum Jenyns. Frequent in the R. Deben, occasionally in the other main rivers. * Pisidium moitessierianum and R. Waveney. Dreissenapolymorpha

Paladilhe. Confined to the R. Stour (frequent)

(Pallas). Oulton Broad and lower R. Waveney only.

Finally, a plea for records. Many species of molluscs (particularly slugs) are synanthropic and are most usually associated with man. Due to a lack of access to sufficient gardens many of these species are under-recorded and, therefore, the distribution maps are not showing the true status of these species in Suffolk. The members of this Society can make a valuable contribution to the present survey by sending me specimens from their gardens. This presents obvious difficulties, but the following guidelines should be of assistance:(i) Packaging - specimens will remain alive for at least a week if put in a polythene bag with some loose damp moss and sealed. Put the bag in a small cardboard box and post, preferably by first class mail. (ii) Data - Include your name, address, date, a six figure grid reference and a brief description of the habitat (e.g. large, old, untidy garden). All letters will be acknowledged with a species list and refunded postage. (iii) Where to Look - Under stones, timber, polythene, on old walls, compost heaps, etc. (iv) Selection of Specimens - Please do not send specimens of the large common garden snail, Helix aspersa, or the large black slug, Arion ater, the records will suffice. Everything eise will be welcome, try to select as much variety as possible. References Davies, S. M. (1979). Segregates of the Arion hortensis complex, with the description of a new species, Arion owenii. J. Conch., Lond. 30,123. Greene, C. (1891). Catalogue of Land and Freshwater Shells of Suffolk. Proc. S u f f . Inst. Archaeol. 7, 275. Kerney, M. P. (ed.) (1976a). Atlas ofthe Non-Marine Mollusca of the British Isles. Institute of Terrestrial Ecology, Cambridge. Kerney, M. P. (1976b). A list of the fresh and brackish water Mollusca of the British Isles. J. Conch., Lond. 29, 26.

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Suffolk Natural History, Vol. 22 36 Kerney, M. P. (1982). Vice-comital censusof the non-marine Mollusca of the British Isles (8th edition). J. Conch., Lond. 31, 63. Killeen, I. J. (1983). Vertigo angustior Jeffreys living in Suffolk. J. Con Lond. 31,257. Mendel, H. & Piotrowski, S. H. (1986). The Butterflies of Suffolk. S Naturalists' Society, Ipswich. Morley, C. (1938). The Mollusca of Suffolk. Trans. Suffolk Nat. Soc. [Note - this account was written by 'our conchological members', but is generally attributed to Morley on the basis of writing and style.] Preece, R. C. (1980). An Atlas of the Non-Marine Mollusca of th Wight. Isle of Wight County Museum Service. Natural History Series No. 1. Sheppard, R. (1823). Descriptions of Land Shells with Observations. Trans. Linn. Soc., Lond. 14,148. Waiden, H. W. (1976). A nomenclatural list of the land Mollusca of the British Isles. J. Conch., Lond. 29, 21. Ian J. Killeen 163 High Road West Felixstowe IP11 9BD

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