Journal of Conchology 41 (5), October 2014

ISSN 2755-3531


Population size, structure and distribution of an unexploited freshwater pearl mussel Margaritifera margaritifera (L.) population in Scotland

Peter J. Cosgrove, Donald M. Shields, Cameron F. Cosgrove, Jackie E. Farquhar, David H. Jarrett, Saskia Jancke, Amy R. Mitchell & Rose M. Moggach

Abstract. All published studies into Scottish populations of the globally threatened and endangered freshwater pearl mussel Margaritifera margaritifera have taken place on exploited (pearl fished) populations. In 2013, detailed studies took place on a large and unexploited freshwater pearl mussel population present in a small, remote Scottish river. This paper outlines the results of this study and compares the size, structure and distribution of this unexploited population with those from exploited Scottish populations.

The unexploited population was estimated to contain approximately 0.6 million freshwater pearl mussels, holding the highest densities of mussels per km of river recorded in Scotland. Assessed against targets for assessing conservation sites, the population would be considered to be in favourable condition, holding high densities of freshwater pearl mussels (up to a mean of 84 mussels per m2 over a 50 m × 1 m transect area; highest density of 216 mussels in 1 m2), a high proportion of juvenile mussels (23% of samples measured) and many juvenile mussels below 30 mm in size. Current population estimates for most exploited Scottish freshwater pearl mussel populations are far lower than former unexploited population estimates suggest.

This unexploited and undescribed population is considered to be the most important freshwater pearl mussel population in Scotland and the UK. Much conservation action is taking place on this species in the UK and this population is a suitable benchmark and reference site for comparisons on what a restored ‘healthy’ freshwater pearl mussel site should resemble. The undescribed population is threatened by a range of factors and these are discussed. The River X freshwater pearl mussel population is of global importance.

Key words. Margaritifera, pearl-fishing, unexploited population, natural reference site

Date of publication. October 2014


New species of land snail, Mirus jejuensis, (Gastropoda: Enidae) from Jeju Island, Korea

Gab Man Park

Abstract. Several specimens of Mirus jejuensis n. sp. were collected alive for the first time from Jeju Island. Based on the new material, shell, radula, genital system and chromosome kartotype are here described. A terrestrial cave snail (Gastropoda: Enidae), Mirus jejuensis n. sp., occurs in Gungi cave on Jeju Island, South Korea and is proposed as a new species in the family Enidae. Diagnostic features of the new species include possession of a minute elongate-conical, sinistral shell, with apical microsculpture comprising low tubercles. The chromosome number and karyotype are 2n = 56 and 8M + 15SM + 5ST, respectively.

Key words. Mirus jejuensis, Korea, Cave snails, Jeju Island, Gastropoda, Enidae

New taxon. Mirus jejuensis Park, 2014

Date of publication. October 2014


Size-dependent predation by otter Lutra lutra on swan mussels Anodonta cygnea (Linnaeus 1758) — observations and radiotelemetry experiment

Katarzyna Zając

Abstract Europe’s increasing populations of medium-size predators pose a potential threat to freshwater mussels in some regions. Live mussels (Anodonta cygnea) collected from the bottom of Zalew Pińczowski reservoir (S Poland) did not differ in size from shells of individuals predated by otters, but the shells of predated individuals varied in size significantly less, suggesting that only the middle size class is predated. A similar size class was predated in a sample of live mussels equipped with radio transmitters and experimentally distributed near an otter den: 10% were eliminated within a month, indicating substantial predation pressure. Older mussels were not attacked or else the attacks were unsuccessful, suggesting that the otter cannot seriously threaten the reproductive-age part of the population, but predation on middle-size individuals might lead to ageing and eventual extinction of populations, especially small and isolated ones.

Key words. Anodonta cygnea, size-selective predation, radio-tracking, otter, Lutra lutra

Date of publication. October 2014


Review of Rhaphaulus L. Pfeiffer 1856 and Streptaulus Benson 1857 species with description of R. tonkinensis n. sp. from Vietnam (Gastropoda: Pupinidae)

Barna Páll-Gergely, András Hunyadi & Wim J. M. Maassen

Abstract. A middle-sized pupinid species was recently discovered in Vietnam and described here as Rhaphaulus tonkinensis n. sp. Its shell is characterized by a thick, rather flat outer tube which turns downwards along the peristome margin. This new species represents the first record of the species from Vietnam. A checklist of Rhaphaulus and Streptaulus taxa, photos of most known species (mainly type specimens) and a comprehensive map are presented. The taxonomic position of the genus Streptaulus is discussed.

Key words. Gastropoda, Cyclophoroidea, Pupininae, taxonomy, Vietnam

New taxon. Rhaphaulus tonkinensis Páll-Gergely, Hunyadi & Maassen, 2014

Date of publication. October 2014


Taurinellushka babugana gen. nov., sp. nov. (Stylommatophora: Pristilomatinae) from the Crimean Mountains (Ukraine) and revision of Crimean Mediterranea (Oxychilinae)

I. Balashov

Abstract. Taurinellushka babugana gen. nov., sp. nov., from Crimea, is described on the basis of shell and anatomical characters. Taurinellushka babugana is close to and compared with Troglovitrea Negrea & Riedel 1968 from the caves of Romania, but is distinguished by the unusual inner structure of the penis and position of the elongated perivaginal gland. The shell is similar to the several other species of Pristilomatinae and Oxychilinae, necessitating a revision of Crimean Mediterranea. Both Hyalina kamia Puzanov 1925 and Hyalinia iphigeniae Lindholm 1926 are confirmed to be the junior synonyms of Mediterranea hydatina (Rossmässler 1838). Taurinellushka babugana is most numerous in the beech forests on the southern slopes of the Babugan mountainous massif. Empty shells were found on the northern slopes, and also on Gurzuf, Chatyr-Dag and Demerdji massifs. All findings were made between 1050–1545 m altitude, contrasting with the coastal distribution of the similar M. hydatina. Taurinellushka babugana is less variable, smaller (up to 3.8 mm against 6.2 mm), with a narrower umbilicus, wider last whorl and lower spire, and is less striated and not pigmented. Nevertheless the shells are very similar to some juveniles of M. hydatina.

Key words. Taurinellushka babugana, Mediterranea, Zonitidae, Crimea, Ukraine

New taxa. Taurinellushka Balashov, 2014; Taurinellushka babugana Balashov, 2014

Date of publication. October 2014


Revision of “Hauffenia jadertina” kuščer 1933, and description of a new species from Pag island, Croatia (Gastropoda: Hydrobiidae)

Luboš Beran, Marco Bodon & Simone Cianfanelli

Abstract. Hauffenia jadertina Kuščer 1933, is revised using material from the type localities and others from Croatia, mostly from the Cetina valley. On the basis of anatomical characters it is attributed to the genus Kerkia Radoman 1978. Hauffenia jadertina sinjana Kuščer 1933, is synonymized with Kerkia jadertina. A new species, attributed to the same genus, Kerkia kareli n. sp., is described from Pag Island in the northern Adriatic Sea (Croatia). It inhabits phreatic waters and, until now, it has been collected only in three wells situated on the island. In this paper, a detailed description of the two species is given.

Key words. Gastropoda, valvatiform Hydrobiidae, Kerkia, taxonomy, Croatia

New taxon. Kerkia kareli Beran, Bodon & Cianfanelli, 2014

Date of publication. October 2014


On the identity of Helix dohrni Paulucci 1882 and Helix hillyeriana Paulucci 1882, with the description of two new Xerosecta species (Pulmonata: Hygromiidae) from Sardinia (Western Mediterranean)

Willy De Mattia & Francesco Mascia

Abstract. The genus Xerosecta (s.s.) is conchologically and anatomically investigated on the island of Sardinia (Western Mediterranean). Xerosecta dohrni (Paulucci 1882) is the most widespread and commonest species on Sardinia. Its reproductive system is characterised by a simple genital atrium without crests or knobs and a long penial flagellum. Paulucci (1882) described Helix hillyeriana from Decimomannu (in the province of Cagliari) and distinguished it from H. dohrni on the base of minor shell features such as a very weak keel and slightly more depressed shape. Nevertheless, no significant genital differences were found amongst keeled and depressed specimens and other populations elsewhere on Sardinia. Thus we consider these keeled populations as ecotypes of X. dohrni (i.e. form hillyeriana). Two new species are described by virtue of their distinctive conchological and anatomical features. Xerosecta sandaliotica n. sp. is easily distinguishable by its large genital atrium containing a large fungiform papilla. So far its distribution is restricted to the Sulcis-Iglesiente region (SW Sardinia). Xerosecta brachyflagellata n. sp. is known only from a single locality in the NE of Sardinia (Golfo Aranci, Olbia-Tempio province). It is distinguished by virtue of its remarkable short penial flagellum.

Key words. Xerosecta dohrni, Xerosecta sandaliotica n. sp., Xerosecta brachyflagellata n. sp., Hygromiidae, Sardinia, Italy, nomenclature, taxonomy, systematics

New taxa. Xerosecta sandaliotica De Mattia & Mascia, 2014; Xerosecta brachyflagellata

Date of publication. October 2014


New records of non-indigenous molluscs in the Mediterranean Basin: two enigmatic alien gastropods from the Tuscan Archipelago (Italy)

Andrea Benocci, Giuseppe Manganelli & Folco Giusti

Abstract. Two alien gastropod species, an assimineid and a succineid, were found in a plant nursery on Elba Island during field research aimed at gathering information on non-native terrestrial molluscs in the Tuscan Archipelago (central Italy). Neither species has been recorded in the Euro-Mediterranean area but their identification is not easy because of taxonomic uncertainty and the absence of a modern revision of these gastropod groups. Details of their anatomy are given for the first time and identification is attempted. The assimineid belongs to the Asian genus Solenomphala Martens 1883, but its specific identification could not be ascertained. The succineid is presumably an invasive species recorded from nurseries in North America, Hawaii and Australia, tentatively identified as Succinea tenella Morelet 1865. Both species were probably introduced with plants imported from tropical Asia. Since alien species are a potential threat to native biodiversity, their settlement in the National Park of the Tuscan Archipelago and other parts of Italy and Europe should be prevented.

Key words. Introduced species, plant nurseries, Solenomphala, Succinea

Date of publication. October 2014


Corrigendum to “Taxonomic revision of Leiostracus onager and Leiostracus subtuszonatus (Gastropoda: Pulmonata: Orthalicidae)” by Salvador & Cavallari (2013)

Rodrigo B. Salvador, Daniel C. Cavallari & Abraham S.H. Breure

Date of publication. October 2014