Journal of Conchology 39 (3), June 2007

ISSN 2755-3531

 

A redescription of Theodoxus schultzii (grimm, 1877), an endemic neritid gastropod of the Caspian Sea
Zettler, M. I.

Abstract
Theodoxus schultzii (Grimm, 1877), one of the rarest gastropod species of the Caspian Sea, is redescribed from recently sampled material. Morphological features are described, with photographs of the shell, operculum and radula. The shell of this species is characterised by its mostly citreous colour and elongation of the apertural edges. In its typical form, it is very similar to other species of the genus. The features of the radula and operculum are very similar to those of T. pallasi Lindholm, 1924 from the Caspian Sea and T. astrachanicus Starobogatov, 1994 from the Volga delta.

Key words: Theodoxus schultzii, Caspian Sea, redescription, morphology, operculum, radula, brackish water.

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Opisthobranchiate mollusca from Ghana: Dendrodorididae and Corambidae
Edmunds, M.

Abstract
Three species of Dendrodorididae and one of Corambidae are described from Ghana, West Africa. Dendrodoris guineana Valdés and Ortea, 1996 is only known from this region but may be part of a cline round the West African coast, currently divided into several species. Another specimen of Dendrodoris was not fully mature and could not be definitively assigned to one of these species. Further material of Doriopsilla albolineata Edmunds, 1968 is described but is here recognised as forming part of a cline from Europe to West Africa. It is therefore considered to be a subspecies, albolineata Edmunds, 1968, of Doriopsilla areolata Bergh, 1880. It is proposed that West Atlantic and Indo-Pacific material which have been considered to be conspecific with D. areolata should be recognised as distinct species, Doriopsilla nigrolineata Meyer, 1977 and Doriopsilla davisi (Allan, 1933) respectively. Corambe testudinaria Fischer, 1889, reported here for the first time from West Africa, occurs on both sides of the Atlantic and may travel widely either on Sargassum or on the hulls of boats. The genera and valid species of the Corambidae are reviewed.

Key words: Atlantic nudibranchs, Corambe, Dendrodoris, Doriopsilla.

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Redescription of the tropical west African pleurobranchid Pleurobranchus reticulatus Rang, 1832 (Gastropoda: Opisthobranchia)
Neves, R., Cervera, J. L. and Calado, G.

Abstract
Pleurobranchus reticulatus Rang, 1832 is redescribed from specimens collected in São Tomé Island (Gulf of Guinea, W. Africa). A detailed description of both the external and internal anatomy is given, in particular of the shell, jaws, radula and, for the first time, the reproductive system. This structure is herein described for the first time. Ontogenetic variation of the colour pattern is also presented. This species is compared with other eastern Atlantic species of this genus.

Key words: Opisthobranchia, Pleurobranchus, Pleurobranchus reticulatus, São Tomé Island, West Africa.

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A review of the aquatic mollusca from Lake Pamvotis, Ioannina, an ancient lake in NW Greece
Frogley, M.R. & Preece, R.C.

Abstract
Lake Pamvotis (= Lake Ioannina) is an ancient lake in NW Greece famous for its long geological record, which has furnished some of the most detailed Quaternary palaeoclimate records from Europe. Unlike some other Balkan lakes, which exhibit spectacular faunal radiations, Lake Pamvotis (and its surrounding habitats) supports just two (but maybe up to five) endemic gastropods but is the type locality for two other valid species of aquatic molluscs and for two taxa now regarded as junior synonyms. It was also an important locality where Schläfli collected specimens later described by Mousson in 1859. These shells, now in Zürich Museum, have been revised as part of a new study of the aquatic fauna of the lake. Four species represented in this collection are not otherwise known from Greece, raising the suspicion that shells from different localities have become mixed. The status of a further two species, known elsewhere in Greece, remains unclear since they have not been re-discovered at Ioannina. A systematic review is given of the 29 species of gastropod and 8 species of bivalve now known from Lake Pamvotis and its surrounding marshlands and springs. Trichonia trichonica is reported from only its second known site and Pisidium obtusale and Gyraulus cf. piscinarum are recorded from Greece for the first time. Illustrations of critical taxa are presented. Planorbis janinensis is transferred to the genus Gyraulus. Eight species of mollusc have been recovered from Holocene sediments beneath the lake; the records for four of these can be traced back to at least 200,000 years. Dreissena stankovici seems to have been present at Ioannina throughout the Quaternary.

Key words: Lake Pamvotis, Ioannina, aquatic molluscs, endemism, Mousson.

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Genus Samacar Iredale, 1936 (Bivalvia: Arcidae) with descriptions of a new subgenus and two new species from the northern Pacific
Kamenev, G.M.

Abstract
A new subgenus, Pseudoporterius, of the genus Samacar Iredale, 1936, and two new species, Samacar (Samacar) kurilensis and S. (Pseudoporterius) aleutica, are described from the Kuril (depth 170-368 m) and Aleutian (depth 70-168m) Islands. The new subgenus has no radial sculpture; the hinge plate is strongly curved, most concave and thin under beaks, strongly widening anteriorly and posteriorly, with horizontal anterior and posterior teeth separated by a very wide edentulous gap with three ligamental grooves. A direct development is inferred for the both new species. They have a very large (length to 640 μm for S. (Samacar) kurilensis and to 790 μm for S. (Pseudoporterius) aleutica), distinctly marked, bowler-shaped prodissoconch. Expanded descriptions of Samacar (Samacar) strabo (Hedley, 1915) are also given.

Key words: Samacar, North Pacific, systematics, new species.

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A new approach to studying and sampling land molluscs: Habitat structure and the effects of scale on land molluscs
Menez, A.

Abstract
Many studies have demonstrated associations between the distributions and diversities of land molluscs at large scales. We know very little, however, about the importance of factors at small scales and almost nothing about the effects of scale variance. Quantitative sampling of land molluscs and measurement of environmental variables at fine scales allows these effects to be studied. Using this approach it is possible to: (1) assess the effects of environmental variables such as components of habitat structure on diversity across scales and, (2) determine sampling efficacy. Data from locations in southern Iberia show that increased heterogeneity is associated with a higher number of species, but not with higher abundances of species, and that there are significant changes across scales for number of species, abundances and diversity.

Key words: Land molluscs, sampling, diversity, heterogeneity, complexity, habitat structure, species estimators, southern Iberia.

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From Aydin mountains, Turkey and the associated land snail fauna
Örstan, A., Yildirim, M. Z., Ceylan, S., Pearce, T. A. & Welterschultes F.

Abstract
Twenty-one native species of land snails were recorded during a survey of the Aydın Mountains in the Province of Aydın, Turkey. Idyla aydinensis Örstan (Pulmonata: Clausiliidae) is described as a new species from an altitude of 1030m. The new species is characterized by a narrow shell with closely spaced fine ribs and a long penis with a grooved pilaster. New records of Turanena hemmeni, Zonites chloroticus, Xeropicta smyrnocretica and Helicigona matrella are given, extending the ranges of these species.

Key words: Gastropod, pulmonate, biodiversity, clausiliid.

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Supplementary data on the marine malacofauna of Zanzibar and Pwani Province in Tanzania; East Africa
Wronski, T.

Abstract
The marine malacofauna, of the Pwani Province in Eastern Tanzania (Dar es Salaam, Mbudya Island) and Zanzibar Island (Nungwi) was studied in 2000. In this paper, known data from Spry (1964, 1968), Sawyer (1999, 2000) and Rosenberg et al. (2004) are supplemented by the results of the author’s fieldwork. A total of 193 gastropod and bivalve species were recorded; 39 were neither recorded by Spry (1964, 1968) nor by Sawyer (1999, 2000), of which 23 species are new for East Africa (Rosenberg et al., 2004). On the basis of the current results and the lack of a comprehensive species list, a more detailed investigation of tropical marine East African malacofauna is recommended.

Key words: Marine fauna, Gastropoda, Bivalvia, Tanzania.

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Chromosome and cytological analysis of the endangered limpet Patella ferruginea Gmelin, 1791 (Gastropoda: Patellidae): taxonomical and monitoring implications
Espinosa, F., Domínguez, I. & Garcia-Gomez, J. C.

Abstract
Cytogenetic data are increasingly being used in taxonomic analyses and can also be used to investigate phylogenetic patterns. Additionally, studies on genotoxicity using cytogenetic analyses have been demonstrated as an useful tool for biomonitoring. The endangered limpet Patella ferruginea was investigated under karyo and cytological analyses in order to explore the taxonomic status of the two different forms of the species, the phylogenetic relationships and to show up its suitability for future biomonitoring programs. The haploid complement was of n = 9 (5 metacentric, 1 meta-submetacentric, 1 submetacentric, 1 subtelocentric, 1 telocentric), and the ideograms of the two forms failed to establish taxonomic separation between them. P. ferruginea is close to P. rustica according to the karyotypes and recent molecular studies. Finally, several nuclear abnormalities have been detected in the species that could be useful for monitoring the cytotoxic effects on the endangered populations of the species.

Key words: Patella ferruginea, chromosome, cytological, rouxi, lamarcki.

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Short Communication
Synonymization of Gulella reesi (Preston, 1914) and Gulella germaini (Connolly, 1929) from West Africa
Oke, O. C.

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Short Communication
Shell wiping in Calliostoma granulatum (Born, 1778)
Holmes, S. P. & Duncan, P. F.

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Book Reviews
Catalogus Fossilium Austriae (Ed. W.E. Piller): Bivalvia Band 1/Teil1-3 (in German) By Ortwin Schultz
Oliver, G.
Catalogue of the Marine Gastropod Family Fasciolariidae by Martin A. Snyder
Brown, K.

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