ISSN 2755-3531
Zoltán Péter Erőss, Zoltán Fehér & Barna Páll-Gergely
Abstract. A new species, Balcanodiscus (Balcanodiscus) danyii n. sp. is described from the Sapka Mountains in Thrakia (northeastern Greece). B. danyii seems to be the smallest species of the Balkan endemic genus Balcanodiscus Riedel & Urbański 1964. According to anatomical data, its closest related species is Balcanodiscus cerberus Riedel 1984. A comprehensive table is presented to summarize the main anatomical and shell characters of known Balcanodiscus species.
Key words. Balcanodiscus danyii, new species, Zonitidae, taxonomy, Greece
Date of publication. December 2011
David T. Holyoak, Geraldine A. Holyoak, Yurena Yanes, Maria R. Alonso & Miguel Ibáñez
Abstract. The endemic Macaronesian Canaridiscus, provisionally placed in the Discidae genus Atlantica, are closely linked to the peculiar laurel forest habitat of these islands. Knowledge of Atlantica (Canaridiscus) is increased here with the description, for the first time, of the genital system of three more of its species. The epiphallus is apparently lacking and the penis is much longer than that known from any of the Discidae of Europe and North America; generally it is too large to be more than partly accommodated in the distal female genital tract. Keraea has been regarded as an endemic Macaronesian genus of Discidae known only from a few shells, but its Madeiran species has been identified as a Trochulus (Hygromiidae) and its type species (from Tenerife) also matches Hygromiidae, not Discidae. The origin and relationships of the Macaronesian Discidae are discussed. The simplest explanatory model is apparently that they represent the last living relicts of a more diverse fauna of Discidae that lived in Europe during the Tertiary; Atlantica (Canaridiscus) was probably isolated early on from the remaining Discidae. Recent literature reports multiple patterns of colonisation of Madeira and the Canaries that have varied between different groups of plants and animals. Hence, it is argued that it is unwarranted to expect to find only the single pattern of colonisation among the land snails of each of these archipelagos that was advocated by Waldén (1984).
Key words. Africa, Atlantica, Canaridiscus, genital anatomy, Laurasia, laurisilva, Macaronesia, Madeira, North America, paleobiogeography, penis length, Tertiary relict
Date of publication. December 2011
Giuseppe Manganelli, Valeriano Spadini & Andrea Benocci
Abstract. The taxonomic and nomenclatural status of the two earliest established Mediterranean Sthenorytis species: Turbo retusus Brocchi 1814 and Turbo trochiformis Brocchi 1814, was re-examined. The identity of Turbo retusus remains uncertain because there are no specimens with certain type status or topotypes on which to designate a neotype. In fact, we agree with de Boury (1890) that Brocchi had no specimens of this species and that he described it on the basis of Monti’s (1746) figure, the specimen of which has been lost. The identity of Turbo trochiformis was clarified, designating the only existing historical topotype as neotype.
Date of publication. December 2011
I.V. Muratov & O. Gargominy
Abstract. Bulimus demerarensis was described by Pfeiffer (1861: 24) from Demerara (now part of Guyana). Drymaeus (Leiostracus) ruthveni was described by H.B. Baker (1926: 48) from the same region (Dunoon) and later was synonymised with Leiostracus (Leiostracus) demerarensis (Pfeiffer 1861) by Breure (1978: 1, 227). Troschel (1849) probably dissected this species under the name Bulimus cinnamomeolineatus, but illustrated only the jaw and the radula. The anatomy of this species remained unknown until 1997 when one snail has been collected alive in French Guiana. Unfortunately, this specimen dried out and had to be re-hydrated in a solution of tri-sodium phosphate. Surprisingly, the re-hydration worked quite well and we are able to illustrate the genital apparatus of this species for the first time. As the result, we are transferring demerarensis Pfeiffer 1861 (syn. ruthveni Baker 1926) from Leiostracus Albers 1850 to Bostryx Troschel 1847.
Key words. Bostryxdemerarensis, Bostryx ruthveni, taxonomic position, French Guiana
Date of publication. December 2011
Opisthobranchiate Mollusca from Ghana: Discodorididae
Malcolm Edmunds
Abstract. Descriptions are given of eleven species of Discodorididae belonging to nine different genera collected in Ghana between 1963 and 1973; seven are described as new species while an eighth is also only known from Ghana but was described by the author over 40 years ago. The remaining three species have been recorded from Europe and east Atlantic islands, so it is probable that many of them will be found to have similar geographical ranges. The secretion of sulphuric acid by Geitodoris tema is described and evidence is presented to confirm that a characteristic of the genus Geitodoris Verrill 1880 is the presence of large acid-secreting subepidermal glands in the notum. There is no evidence at present that the superficially similar subepidermal glands of Paradoris also secrete acid. Five of the eleven species belonging to the genera Baptodoris, Jorunna and Rostanga have well-developed caryophyllidia covering the dorsal surface which give them a texture similar to that of sponges.
Key words. Atlantic nudibranchs, Discodorididae, Ghana
Date of publication. December 2011
A new species of Ervilia from north Brazil (Bivalvia, Semelidae)
Rodrigo Cesar Marques & Luiz Ricardo L. Simone
Abstract. Ervilia asymmetrica is a new species described for the Northern Coast of Brazil. A more elongated outline and an umbo more asymmetrical are main diagnostic characters of this taxon. Comparison with other Western Atlantic species of this genus is also performed.
Key words. Ervilia asymmetrica, new species, Western Atlantic, Brazil, Semelidae
Date of publication. December 2011
Katrin Schniebs, Peter Glöer, Maxim V. Vinarski & Anna K. Hundsdoerfer
Abstract. Radix balthica is a morphologically very variable species that is often very difficult to determine on the basis of the shell characters. Since DNA-taxonomy is still expensive and requires much more time than anatomical determination, and the methodology is hardly available for most colleagues that work faunistically, this work aims to broaden knowledge of the intraspecific variability in the more important systematic characters used for determination of Radix balthica. To find reliable distinguishing characters from other Radix-species, an integrative approach was sought and data from three different sources were acquired for analysis. Molecular sequence data of the gene fragments ITS-2 and/or cyt-b was obtained for 58 individuals in order to study the species identity of Radix balthica (Linnaeus 1758). Of the subsample of 24 individuals for which both gene fragments were available, the variability of several characters that are commonly used for determination was documented. These include shell morphology, mantle pigmentation, shape and position of the bursa copulatrix, length and position of the bursa duct, and length ratio of praeputium to penis sheath. Morphological distinguishing characters from R. auricularia, R. labiata, R. lagotis and R. ampla are discussed and summarised in a table. Analysis of the network of haplotypes (cyt-b) shows that there is no distinct correlation to the geographic distribution pattern.
Key words. Radix balthica, R. auricularia, R. labiata, R. lagotis, R. ampla, morphology, molecular genetics, Variation
Date of publication. December 2011
Ensis directus (Conrad 1843) (Bivalvia: Solenoidea) found in Liverpool Bay (Sea Area S24) [Short Communication]
Date of publication. December 2011
Bernard Verdcourt (1925–2011) – an appreciation, obituary, malacological names and bibliography [Obituary]
B. Rowson, P. Tattersfield, J. Gallichan & B. Verdcourt†
Bernard Verdcourt (20.1.1925–25.10.2011)
Date of publication. December 2011