ISSN 2755-3531
Adrian T. Sumner
Abstract. Polymorphisms for shell colour and pattern in Cernuella virgata are illustrated. Populations of C. virgata in north-east England are described in which white shells are predominant in an open habitat exposed to the sun, and brown shells occur more commonly in shaded sites. This could well be a result of climatic selection. Other populations of C. virgata in north-east England and on the east coast of Scotland do not show any correlation with microclimate, and it is suggested that other factors such as founder effects and evolutionary bottlenecks might be responsible for the present day incidence of different shell pattern morphs.
Key words. Cernuella virgata, polymorphism, climatic selection, founder effect, evolutionary bottleneck
Date of publication. April 2018
Luiz Ricardo L Simone
Abstract. Pilsbrylia dalli is a new species belonging to a genus previously only known in northern Argentina (1800 km to the east) but recently discovered in Vazante region, Minas Gerais, Brazil. The new species has a diagnostic set of features: shell relatively obese; last two whorls similar in size; the apex relatively wide; the sculpture with delicate axial ribs, located close to each other (around 30 in penultimate whorl); the peristome with strong, wide labral tooth, and a tall and flattened palatal tooth. Further comparison with the other two species of the genus, P. paradoxa and P. hyltonae, is also provided, including images of their type specimens.
Key words. Morphology, Pilsbrylia dalli n. sp., Odontostomidae, Brazil, biogrography
New taxon. Pilsbrylia dalli Simone, 2018
Date of publication. April 2018
Evolution and taxonomy of the populations of Eremina (Gastropoda, Pulmonata: Helicidae) in Morocco
David T. Holyoak, Geraldine A. Holyoak, Luis J. Chueca & Benjamín J. Gómez Moliner
Abstract. The taxonomy and nomenclature of Moroccan Eremina (Helicidae) is revised, mainly on the basis of extensive new collections made in 1986 and 2016. Molecular data from the recent collections supplemented interpretations based on study of shells and genital anatomy. Four Moroccan species are recognised here: the localised E. dillwyniana s.s. (S. of El Ouatia [ = Tan-Tan Plâge] to Tarfaya) and the widespread E. duroi (near Sidi Ifni southwards to N. Mauritania) have rounded shells with low spires and live in a relatively humid zone prone to sea mists just inland of the Atlantic coast. E. vermiculosa has a subglobular shell and occurs further inland around the range of E. dillwyniana and the northern part of that of E. duroi (from near Guelmim to region SW. of Tan-Tan). E. inexspectata with keeled shells has a small range in rocky sandstone hills from the Oued Draa southwards to near Tan-Tan, separating two groups of populations of E. vermiculosa. Populations comprised mainly of intergrades (presumed hybrids) occur in a narrow zone where the ranges of E. duroi and E. vermiculosa meet. Intergrades of E. inexspectata with E. vermiculosa occur within populations of the former species. Subfossil (Quaternary) shells show that the ranges of both E. duroi and E. vermiculosa formerly extended further inland, into desert regions now too arid and sparsely vegetated to support either taxon; fossils also demonstrate past occurrence of E. vermiculosa at a site that now has living E. inexspectata. Subfossil shells of the apparent hybrid of E. duroi with E. vermiculosa suggest that hybridization occurred when they met in the past, far outside the modern range of either species. Treatment of all four forms at species rank is based on the very narrow modern hybrid zones between E. duroi and E. vermiculosa and evidence that their hybridization elsewhere during the Quaternary did not lead to widespread introgression. Nevertheless, lack of sympatry, evidence of repeated hybridization where forms meet, the rather small differences in habitats, lack of differences in genital morphology and sometimes unresolved DNA sequences may imply that the speciation process in these taxa is incomplete. Possible explanations for the evolution of different shell shapes are discussed: the clearest environmental correlation of shell type being with high humidity near the coast (low-spired shells) and much lower humidity inland (subglobular shells with larger apertures). The narrow zones of hybridization apparently imply that intermediate shell types are at a disadvantage.
Key words. Eremina, Helicidae, Morocco, Sahara, shell shape, genital anatomy, DNA, phylogeny, taxonomy, species limits, hybridization, distribution, habitats
Date of publication. April 2018
I. Balashov, S. Kramarenko, D. Shyriaieva & O. Vasyliuk
Abstract. Brephulopsis cylindrica (Menke 1828), a snail native to the Crimea, has been expanding northward and westward, and has recently reached Western Ukraine. Three adjacent and abundant colonies have been found in the tovtrs (small rocky hilltop areas of protected relic steppic habitat) of the Podilski Tovtry National Nature Park in Western Ukraine. These sites and ten similar sites without B. cylindrica were sampled. Most of the snail species that occur in the other ten sites were absent from the samples from the sites with B. cylindrica, which have much lower molluscan diversity. It is suggested that B. cylindrica is excluding some threatened native snails that have comparable ecological preferences, notably Helicopsis striata. Possible mechanisms of competition with native species are discussed. The most likely explanation is that these native snails are displaced from seasonal refuges in rock crevices as a result of the high densities of B. cylindrica. The snails in Western Ukrainian populations of B. cylindrica are smaller than in populations from the Crimean mountains, but similar in size to populations from the Crimean plains, which may be where they originated.
Key words. Competition, exclusion, conservation, terrestrial molluscs, grasslands, Brephulopsis cylindrica
Date of publication. April 2018
Terrestrial mollusks from the region of Corumbá and Maciço do Urucum, SW Brazil
Rodrigo B. Salvador, Eduardo Colley & Luiz R.L. Simone
Abstract. The city of Corumbá and the neighbouring Maciço do Urucum are located in SW Brazil, at the border with Bolivia. The peculiar biogeographic location, the fact that it is inserted in the unique Pantanal biome and the environmental disturbances caused by mining activities make this area interesting for faunal studies. Since no such studies exist for terrestrial gastropods from this region, herein we studied newly collected material from it alongside historical specimens from several museum collections. Since Corumbá is type locality of several species, examination of type material allowed a taxonomic revision of them. Here, we list 19 species from Corumbá and Urucum and synonymize three of the region’s supposed endemics: Drymaeus lynchi Parodiz, 1946 is considered synonymous with D. poecilus (d’Orbigny, 1835); Megalobulimus bereniceae (Morretes, 1952) is considered synonymous with M. intertextus (Pilsbry, 1895); Solaropsis paravicinii (Ancey, 1897) is considered synonymous with S. heliaca (d’Orbigny, 1837). Helicina fulva d’Orbigny, 1835 is reported for the first time in Brazil and the following three species have their first record from Mato Grosso do Sul state: Aperostoma inca (d’Orbigny, 1835), Naesiotus montivagus (d’Orbigny, 1835) and Orthalicus phlogerus (d’Orbigny, 1835).
Key words. Bolivia, Mato Grosso do Sul, Pantanal, Pulmonata, type locality.
Date of publication. April 2018
Vesna Štamol, Giuseppe Manganelli, Debora Barbato & Folco Giusti
Abstract. Hypnophila zirjensis n. sp. is decribed from the Island of Žirje (Šibenik Archipelago, Croatia). The new species is characterized by shell and genital features, which distinguish it from the other Balkan species. These characters match those of species occurring in the western Mediterranean region making the new species very interesting from a biogeographical point of view.
Key words. Land snails, new species, Balkan Peninsula, taxonomy, biogeography
New taxon. Hypnophila zirjensis Štamol, Manganelli, Barbato & Giusti, 2018
Date of publication. April 2018
G. Thomas Watters
Abstract. The genus Gyraxis in Hispaniola is reviewed, currently only known from the area of the Bahía de Samaná in the Dominican Republic. It includes three taxa: Gyraxis samana (Clench, 1966), G. sericata (Pilsbry, 1903) and G. excalibur new species. The radular morphology and isolation from Cuban Gyraxis suggest they may yet require a new genus.
Key words. Urocoptidae, Hispaniola, Dominican Republic, systematics, Gyraxis
New taxon. Gyraxis excalibur Watters, 2018
Date of publication. April 2018
Juvenile Kerry Slugs (Geomalacus maculosus) observed living inside fungal fruiting bodies for the first time [Short Communication]
A. O’Hanlon & M.J. Gormally
Date of publication. April 2018
Two invasive brackish water mussel species in Sweden: Rangia cuneata (G. B. Sowerby I) and Mytilopsis leucophaeata (Conrad) [Short Communication]
Ted von Proschwitz
Date of publication. April 2018
Book review: Molluscs in Archaeology: Methods, Approaches and Applications, edited by Michael J. Allen. 2017
Daniella E. Bar-Yosef Mayer
Date of publication. April 2018
C. Phillip Palmer (1927–2016) [Obituary]
Neale Monks
Date of publication. April 2018
Elizabeth Anne Platts (1937–2017) [Obituary]
Date of publication. April 2018
Stella Maris Turk, MBE (March 27 1925–April 3 2017) [Obituary]
Janice Light
Date of publication. April 2018