Journal of Conchology 41 (3), May 2013

ISSN 2755-3531


Three undescribed species of Napaeus (Gastropoda: Pulmonata: Enidae) From La Gomera (Canary Islands), the richest centre of species radiation for the genus 

Jesús Santana, Miguel Artiles, Yurena Yanes, Francisco Deniz, Maria R. Alonso & Miguel Ibáñez

Abstract. Three new species of the genus Napaeus (Albers 1850) are described from La Gomera (Canary Islands). This is one of the smaller islands of the archipelago but it has the highest number (26) of living species of the genus. Shells of Napaeus species on La Gomera include the shortest, the most slender, the longest and the widest in the genus and show significant diversity in shell colour. Moreover, the Napaeus species from La Gomera exhibit more different patterns of genital system anatomy (five) than the whole of the genus in all the other Canary Islands together (four patterns, one of which is also present on La Gomera). Hesse’s subgenera Napaeus and Napaeinus correspond to two of the eight anatomical patterns involved. At least adults of N. doloresae n. sp. and juveniles of the other new species described can disguise their shells with a cover of soil, apparently to reduce predation.

Key words. Napaeus, taxonomy, species radiation, insular endemics, genital anatomy, shells, shell disguise

New taxon. Napaeus doloresae Santana et al., 2013

Date of publication. May 2013


Shell characters and genital anatomy of Atlantica calathoides and transfer of the genus Atlantica from Discidae to Gastrodontidae (Gastropoda: Pulmonata)

R.A.D. Cameron, G.A. Holyoak, D.T. Holyoak, Y. Yanes, M.R. Alonso & M. Ibáñez

Abstract. The genus Atlantica from the Madeiran Islands contains two species, A. gueriniana, endemic on Madeira Island and A. calathoides, endemic to the Desertas. They have been regarded as members of the Discidae. The hitherto unknown genital anatomy of A. calathoides is described here from study of specimens collected on Deserta Grande. Comparisons with Janulus bifrons (Gastrodontidae) from the same island show that they have very similar genital systems, from which it is evident that both species belong to the Family Gastrodontidae. The Discidae of the Canary Islands have been placed provisionally in Atlantica subgenus Canaridiscus. Since the Madeiran Atlantica species are transferred to the Gastrodontidae, Canaridiscus is raised to generic rank in the Discidae. The “accessory duct” connecting penis and oviduct of Janulus bifrons and Atlantica calathoides (a structure regarded as a unique autapomorphy supporting the monophyly of the Gastrodontidae) is not a duct connection but a transverse bridge.

Key words. Madeiran Islands, Janulus bifrons, Atlantica, Deserta Grande, Canary Islands, Canaridiscus

Date of publication. May 2013


Taxonomic notes on Euro-Siberian molluscs. 5. Valvata (Cincinna) ambigua Westerlund 1873 — a distinct species of the group of Valvata piscinalis O.F. Müller 1774

Maxim V. Vinarski, Peter Glöer, Svetlana I. Andreyeva & Ekaterina A. Lazutkina

Abstract. The taxonomic identity of Valvata ambigua Westerlund 1873 has been examined by using the type materials and samples of snails collected in Europe (Northern Germany) and Western Siberia. V. ambigua is considered to be a distinct species closely allied to Valvata piscinalis O.F. Müller 1774. It can be distinguished from the latter by differences in shell shape and growth patterns. The characteristic features of the two species are stable under conditions of syntopy and therefore these can be regarded as two biologically meaningful entities, or biospecies. The range of V. ambigua covers north, central and eastern Europe and the south part of western Siberia. 

Key words. Valvata ambigua, Valvatidae, taxonomy, distribution.

Date of publication. May 2013


Assiminea zubairensis n. sp. — a new species from Iraq (Mollusca: Gastropoda: Assimineidae)

Peter Glöer & Murtada D. Naser

Abstract. During ongoing malacological investigations of the fauna of the Iraq we found an Assiminea species new to science, which we describe here as Assiminea zubairensis n. sp. To find out if this is in fact a new species we studied the work of Abbott (1958) and Brandt (1974). Both of these authors mentioned the anatomy and depicted the species in photographs which allowed us to compare our Assiminea species with species already known. In addition we compared the species with A. mesopotamica Glöer, Naser & Yasser 2007.

Key words. Assiminea, Assiminea zubairensis n. sp., Iraq

New taxon. Assiminea zubairensis Glöer & Naser, 2013

Date of publication. May 2013


New records of freshwater gastropods from Algeria with the re-description of Bithynia numidica Bourguignat 1864 (Gastropoda: Bithyniidae)

Peter Glöer & Slimane Bouzid

Abstract. Recently (2009–2010) collected freshwater molluscs in NE Algeria revealed 8 species of freshwater gastropods, of which Stagnicola fuscus (C. Pfeiffer 1821) is new for this region. In addition we found Bithynia numidica Bourguignat 1864, which has not been mentioned in the literature since its original description, which we compared with syntypes of Bithynia numidica. So we can provide the anatomy of the species under discussion for the first time.

Key words. Redescription, anatomy, syntypes, Bithynia numidica

Date of publication. May 2013


A new Oxychona species (Gastropoda: Pulmonata: Orthalicidae) from Bahia State, Brazil

Rodrigo Brincalepe Salvador & Daniel Caracanhas Cavallari

Abstract. Part of the private collection of the late public health physician and shell collector Jorge Faria Vaz was recently donated to the Museu de Zoologia da Universidade de São Paulo (MZSP; São Paulo, Brazil). A new species of pulmonate land snail, Oxychona maculata sp. nov. (Orthalicidae), was found in this collection and is herein described. The species stems from Bahia state, Brazil, a place that has been revealing many new land snail species, which also shows how little this fauna is known. Finding a new species in an old collection is a stark reminder of the importance of museum collections. Unfortunately, it is not known if Oxychona maculata can still be found in the wild, but it is a reminder that the remaining fragments of the Atlantic forest can house many endemic species and, therefore, should be properly preserved.

Key words. Bulimulinae, Ilhéus, Bahia State, Oxychona maculata sp. nov.

New taxon. Oxychona maculata Salvador & Cavallari, 2013

Date of publication. May 2013


Karyotypic analysis of the terrestrial snail genus Phuphania (Pulmonata: Yakiidae) with description of a new species from Thailand 

Bangon Kongim & Somsak Panha

Abstract. The dyakiid genus Phuphania is reported for the second time and a new species Phuphania carinata is described from a limestone mountain at Phu Kiew National Park, Chaiyaphum Province, Thailand. The first species described, the nominotypic species Phuphaniaglobosa, and the current new species described here, P. carinata, were karyotyped for the first time and showed distinct inter-specific differentiation in the diploid chromosome number and karyotypic formula (P. carinata: 2n = 64 and 5 m + 5sm + 21t + 1a; P. globosa: 2n = 66 and 7 m + 12sm + 14t). The new species has a semiglobose, pale fulvous, shell, a black ground body colour with cream spots all over the body, remarkable fine radial growth lines and the amatorial organ gland has two lobes forming a cluster of numerous ducts. The comparison of shell, radula and genitalia morphology, plus the karyotype and habitats of P. carinata new species with P. globosa are discussed. 

Key words. Systematics, Phuphania, Dyakiidae, new species, karyotype, Thailand

New taxon. Phuphania carinata Kongim & Panha, 2013

Date of publication. May 2013


A new species of Euglandina (Pulmonata, Spiraxidae) from Brazil

Jaime Alberto Jardim, Daniel Abbate & Luiz Ricardo L. Simone

Abstract. Euglandina irakita is a new species described from the state of Pará, Northern Brazil, collected in the Amazon Rainforest. The description is based on shell features, and some striking differences from the other species were detected. The new species is the second record of this genus in Brazilian territory. It is characterized by a relatively small size, with an oblong outline, deep sutures and a narrow aperture. A comparison with other species of Euglandina is provided.

Key words. Euglandina irakita n. sp, Pulmonata, Amazon Rainforest, Brazil

New taxon. Euglandina irakita Jardim, Abbate & Simone, 2013

Date of publication. May 2013


New and old species of Benimakia (Neogastropoda: Fasciolariidae) and a description of Nodolatirus, new genus

Philippe Bouchet & Martin Avery Snyder

Abstract. There are at present ten Recent species assigned to the neogastropod genus Benimakia. We describe Benimakia nux n. sp. and Benimakia vermeiji n. sp., both from New Caledonia, and Benimakia rubus n. sp. from Vanuatu. We discuss other species in this genus from New Caledonia, reassigning Turbinella mariei Crosse 1869, from New Caledonia, and Latirus (Peristernia) sowerbyi Melvill 1907, from the Tuamotus and Marshall Islands, to the genus Benimakia. Radulae are studied for six species presently assigned to this genus and, based upon those studies, “Benimakia nodata” [Murex nodatus Gmelin 1791] is made the type of a new peristerniine genus Nodolatirus, which also includes the Austral Islands endemic Nodolatirus rapanus n. sp., the West Pacific Turbinella recurvirostra Schubert & Wagner 1829, and the South African and Indian Ocean Latirus robillardi Tapparone-Canefri 1879.

Key words. Gastropoda, Fasciolariidae, Benimakia, new species, Nodolatirus, new genus, New Caledonia, Vanuatu, Austral Islands

New taxa. Benimakia nux Bouchet & Snyder, 2013; Benimakia vermeiji Bouchet & Snyder, 2013; Bouchet & Snyder, 2013; Benimakia rubus Bouchet & Snyder, 2013; Nodolatirus Bouchet & Snyder, 2013; Nodolatirus rapanus Bouchet & Snyder, 2013

Date of publication. May 2013


Opisthobranchiate Mollusca from Ghana: Dorididae and Cadlinidae

Malcolm Edmunds

Abstract. Descriptions are given of seven species of Dorididae and one of Cadlinidae from Ghana. Three of the species assigned to the genus Doris are poorly known so have not been named. Two new species are described, Doris kpone and Doris minuta, and further information is given of three species known from elsewhere in the Atlantic Ocean, Doris verrucosa Linnaeus 1758, Doris morenoi Ortea 1989 and Aldisa smaragdina Ortea, Perez & Llera 1982. 

Key words. Dorididae, Cadlinidae, Doris, Aldisa

New taxa. Doris kpone Edmunds, 2013; Doris minuta Edmunds, 2013

Date of publication. May 2013


Description of Atopomya dolobrata gen. et sp. nov.: first record of bacterial symbiosis in the Saxicavellinae (Bivalvia)

P. Graham Oliver

Abstract. A new genus and species of the subfamily Saxicavellinae, Atopomya dolobrata, is described from deep water in the north eastern Atlantic. The ctenidia have greatly extended abfrontal surfaces, lined with bacteriocytes that harbour symbiotic bacteria. The anatomy of Atopomya and Saxicavella jeffreysi, Winckworth indicates that Saxicavellinae may have greater affinity with the Basterotiidae rather than the Hiatellidae. This is the first record of bacterial symbiosis in the Saxicavellinae.

Key words. Atopomya gen. nov., bacterial symbiosis, Saxicavellinae, Basterotiidae, Galeommatoidea

New taxa. Atopomya Oliver, 2013; Atopomya dolobrata Oliver, 2013

Date of publication. May 2013


The effects of diet, temperature and salinity on survival of larvae of the fluted giant clam, Tridacna squamosa

M.L. Neo, P.A. Todd, S.L-M. Teo & L.M. Chou

Abstract. Giant clams have been cultured for decades, yet few formal studies have examined their reproduction and early life history. Here we present two experiments that provide baseline information on the effects of micro-algal feeding, temperature and salinity on fertilization success and development of the fluted giant clam, Tridacna squamosa. The effect of different micro-algae feeds, i.e. Tetraselmis suecica (CS-187), Chaetoceros mulleri (CS-176), and yeast, on veliger survival was tested. A mixed-algal diet of 1:1 v/v T. suecica + C. mulleri + yeast resulted in approximately double larval survival by 24 h but no significant differences were identified between the uni-algal and mixed-algal diets at 48 h. Temperature and salinity were examined using a 2 × 2 design; with temperatures of ~22.5°C and ~29.5°C, and salinities of 27‰ and 30‰. At ~29.5°C fertilization success was significantly greater than at ~22.5°C, but higher temperatures were detrimental to the development of trochophores. There were no significant differences in either embryo or trochophore numbers for the salinities tested. The results indicate that both micro-algal diet and temperature can affect T. squamosa larval initiation and development; knowledge that can be used to improve their mariculture.

Key words. Algal particulate food, mariculture, giant clam, Tridacna, larval biology, Singapore

Date of publication. May 2013


Ecological mediators for the gregarious behaviour of Achatina fulica (Mollusca; Achatinidae)

Marta Luciane Fischer, Eduardo Colley, Maria Fernanda Caneparo, Adam Coelho De Aguiar & Francisco De Assis Marques

Abstract. The Giant African Land snail, Achatina fulica Bowdich 1822, which is regarded as one of the 100 worst invasive species in the world, has evolved on the edges of tropical forests, where it has developed its general characteristics showing an ability to adapt to a variety of environments. The objective of this study has been to evaluate the ecological mediators of aggregation, both among wild and captive animals. The sample consisted of 3623 specimens that had shown a preference for isolation illustrating the fact that aggregation is not a set pattern for this species, but rather, a strategy that varies, depending on the site, the season, maturity of the animal and the substrate. This suggests that there is a link between aggregation and factors such as protection, reproduction and overpopulation. Homing and aggregation with the same co-specifics were found to be common since both the co-specifics and the substrate can be employed as a means of orientation through the environment and are a way of locating the areas used for feeding, reproduction and shelter. The data from this study provides evidence that the gregarious behaviour of A. fulica is a complex mechanism mediated by a wide range of ecological factors. The behaviour is a strategy used for its protection and adaptation to different substrates and environmental conditions and can thus maximize its invasive potential. 

Key words. Chemoreception; homing; intraspecific interactions; substrate selection

Date of publication. May 2013


Some ecological peculiarities of Anisus vorticulus (Troschel 1834) (Gastropoda: Planorbidae) in northeast Germany

Michael L. Zettler

Abstract. During the EU Habitats Directive monitoring between 2008 and 2010 the ecological requirements of the gastropod species Anisus vorticulus (Troschel 1834) were investigated in 24 different waterbodies of northeast Germany. 117 sampling units were analyzed quantitatively. 45 of these units contained living individuals of the target species in abundances between 4 and 616 individuals m-2. More than 25.300 living individuals of accompanying freshwater mollusc species and about 9.400 empty shells were counted and determined to the species level. Altogether 47 species were identified. The benefit of enhanced knowledge on the ecological requirements was gained due to the wide range and high number of sampled habitats with both obviously convenient and inconvenient living conditions for A. vorticulus. In northeast Germany the amphibian zones of  sheltered mesotrophic lake shores, swampy (lime) fens and peat holes which are sun exposed and have populations of any Chara species belong to the optimal, continuously and densely colonized biotopes. The cluster analysis emphasized that A.  vorticulus was associated with a typical species composition, which can be named as “Anisus-vorticulus-community”.  In compliance with that both the frequency of combined occurrence of species and their similarity in relative abundance are important. The following species belong to the “Anisus-vorticulus-community” in northeast Germany: Pisidium obtusale, Pisidium milium, Pisidium pseudosphaerium, Bithynia leachii, Stagnicola palustris, Valvata cristata, Bathyomphalus contortus, Bithynia tentaculata, Anisus vortex, Hippeutis complanatus, Gyraulus crista, Physa fontinalis, Segmentina nitida and Anisus vorticulus. Six other species could be assigned as “facultative members” of the “Anisus-vorticulus-community”.

Key words. Anisus vorticulus, Planorbidae, EU Habitats Directive, ecological requirements, community, northeast Germany

Date of publication. May 2013


Coexistence or spatial segregation of some Vertigo species (Gastropoda: Vertiginidae) in a Carex rich fen in Central Poland?

Anna Jankowiak, Rafał Bernard

Abstract. The paper describes the occurrence of an assemblage of Vertigo, composed of four species, Vertigo moulinsiana, V. angustior, V. antivertigo and V. pygmaea, in a small patch of habitat in the degraded environs of Konin, central Poland. The survival of this assemblage in an area strongly affected by human impact has resulted from the microhabitat diversity in the fen and the high quality of the surrounding matrix. Relatively high numbers of V. angustior in the temporarily disturbed part of the fen additionally show that it can inhabit areas subject to occasional and extensive human use. Spatial relations between fen-dwelling species, especially between the most abundant V. moulinsiana and V. angustior, were considered in the context of their preferences for particular habitat conditions relating to the ground moisture levels and microclimate. These seemingly coexisting species were almost completely separated in space, both vertically and horizontally, occupying different meso- and microhabitats.

Key words. Terrestrial snails, microhabitat selection, habitat fragmentation, Vertigo moulinsiana, Vertigo angustior

Date of publication. May 2013


A survey of ancient woodland indicator molluscs in selected sites on the Isle of Man

Keith N. A. Alexander & A. Dubbeldam

Abstract. A week was spent in August 2011 exploring a selection of wooded ravines for ancient woodland indicator species of mollusc. The site selection was based on ravines where botanical survey has suggested ancient woodland conditions. A total of 36 mollusc species were found across the eight study sites. The majority of species found are natives, with only 2 non-native species recorded at these sites—the mollusc fauna appears to be virtually pristine at present. Four of the six ancient woodland indicators already known from the Island were encountered: Limax cinereoniger, Zenobiella subrufescens, Acicula fusca, Leiostyla anglica. The first is the most significant discovery as it had not been reported since it was originally added to the Island’s list over 100 years previously. Two species Spermodea lamellata and Vertigo substriata were not found. Snails in particular were often found in notably low numbers, often just one specimen of a species. The survey was very much an initial exploration, and more detailed investigation is clearly needed in order to find overlooked species and to clarify the pattern of occurrence at site level. 

Key words. Mollusca, ancient woodlands, nature conservation, Isle of Man.

Date of publication. May 2013


Book review: European non-marine molluscs, a guide for species identification, by F.W. Welter-Schultes

Dietrich Kadolsky

Date of publication. May 2013