ISSN 2755-3531
2011-40501
Bulgaria, a hot spot of biodiversity (Gastropoda: Rissooidea)?
Peter Glöer & Dilian Georgiev
Abstract. It is demonstrated that the diversity of Bythinella species in Bulgaria is higher than was formerly realised. The Balkan Peninsula is probably a major centre of endemicity for the genus Bythinella, and more species are expected, as some of the localities pointed out in the old literature were not investigated (Vitosha Mts, Petrokhan Pass in Stara planina Mts). We found eleven new Bythinella spp., 7 species in springs and 4 species in small streams. The vertical spread of Bythinella spp. in Bulgaria is not wide, with 14 species living below 1000 m a.s.l., 13 of them below 500 m, and only 3 species reaching springs higher than 1000 m. Multivariate cluster analysis reveals the distinctness of the newly described species and an identification key to the 17 Bythinella spp. known so far from Bulgaria is provided.
Key words. Bythinella, non-adaptive radiation, Bulgaria, Rissooidea
Date of publication. August 2011
2011-40502
First records of Truncatellina species from Arabia (Gastropoda: Vertiginidae)
Bernhard Hausdorf & Torsten Wronski
Abstract. There were no records of Truncatellina species from the Arabian Peninsula so far. We report two Truncatellina species from the ‘Asir Mountains in southwestern Saudia Arabia. Truncatellina asirensis n. sp. is characterised by a very small, finely striate shell of 4.5–5 whorls, a callous palatalis that is visible in frontal view and low, deeply situated parietal and columellar denticles. The second Truncatellina species is a very small, edentate, ribbed form that resembles T. brandti Zilch 1960 from the Cyrenaica and T. linearis (Lowe 1852) from Madeira in size and sculpture.
Key words. Truncatellina, Vertiginidae, systematics, Saudi Arabia
Date of publication. August 2011
2011-40503
Luboš Beran & Michal Horsák
Abstract. Recent record of a threatened planorbid gastropod Gyraulus rossmaessleri (Auerswald 1851) in northwestern Bohemia has stimulated further ecological research since this species occurs in the Czech part of the Elbe River basin only in this area. A detailed research of the species’s distribution and habitat preferences in northwestern Bohemia were conducted in 2008–2010. Occurrence of G. rossmaessleri was confirmed in the surroundings of Teplice town at 35 out of 123 sites under study. We found that G. rossmaessleri in this area inhabits different types of temporary wetlands and was also often found in small wetlands in spring areas and in small and slowly flowing rivulets. This habitat preference has not been reported so far.
Key words. Gyraulus rossmaessleri, Gastropoda, Planorbidae, northwestern Bohemia, distribution, habitat preferences
Date of publication. August 2011
2011-40504
Ian J. Killeen & Evelyn A. Moorkens
Abstract. Important populations of Vertigo angustior have been discovered in the Blyth Estuary, Suffolk, England. The habitat for the snail has been created and maintained by the presence of man-made sea walls that spread over more than 30 km. This paper outlines the distribution of the species in the estuary, and its location and microhabitats in the context of the sea wall structures.
Key words. Vertigo angustior, ecology, distribution, Habitats Directive
Date of publication. August 2011
2011-40505
Tereza Kořínková
Abstract. A population of the viviparous freshwater bivalve Sphaerium corneum L. from an artificial mill race subjected to irregular changes of water level was investigated using quantitative monthly sampling, paraffin histological sections and chromosome preparations. Unlike most of the previously studied populations of the genera Sphaerium and Musculium, that presented in this paper exhibits less synchronised life-spans. Despite two main birth periods, many specimens also release their broods individually during the season. An adult usually breeds at least twice in a season. The life span is more than one, usually one and a half years. All age and length classes are able to overwinter. Spermatogenesis and oogenesis apparently proceeds simultaneously from spring to autumn and they occur also in fully developed larvae which are still retained inside their parents’ gills. Relationships between the observed breeding strategy and fluctuations of the environment are discussed, as well as the intraspecific and interspecific variation in life-history traits within the Sphaeriidae.
Key words. Sphaerium, life-history, gametogenesis, precocious maturation
Date of publication. August 2011
2011-40506
Anna M. Lipińska, Maria J. Gołąb, Adam M. Ćmiel
Abstract. Vertigo moulinsiana is a little known, but very rare, small land snail species, living in wet areas with high pH and calcium content. The paper presents research carried out in May 2008, on one of the few sites of this species in Poland: in wetlands located in the valley of the Nida river. Based on data collected in 60 randomly selected points, it was found that Vertigo moulinsiana occurred most often and in the highest densities in places overgrown with Glyceria and sedge Carex. The occurrence of the highest density in Glyceria was under “wet” conditions. In sedge, the highest density was noted in “dry” conditions. Also affecting the differences in the population density of snails are the interactions between the type of vegetation and dampness of the conditions, which probably provide suitable microclimatic conditions for snails. Most likely, the presence of Desmoulin’s whorl snail is linked with the spatial structure of vegetation occurring under particular hydrological conditions, which allows for the development of a specific microclimate.
Key words. Vertigo moulinsiana, Polish wetlands, occurrence, vegetation, soil moisture
Date of publication. August 2011
2011-40507
Phylogenetic analysis of some Chinese freshwater Unionidae based on mitochondrial COI sequences
Jiexiu Ouyang, Xiaoping Wu, Shan Ouyang, Shaobo Li & Daxian Zhao
Abstract. In the present study, the mitochondrial COI sequences were sequenced for 43 unionid individuals, belonging to 13 species from 7 genera. Sequences were analyzed using Sequencer 4.05 software. Genetic distances were calculated using the Kimura 2-parameter model. The average intraspecific distance found was 0.02623, much lower than the average interspecific distance, which was 0.18472. The interspecific distance between Anodonta woodiana elliptica and Anodonta woodiana pacifica was only a little higher than the intraspecific distance. This suggests that Anodonta woodiana elliptica and Anodonta woodiana pacifica are not separable as either subspecies or species. A molecular phylogeny of the Chinese freshwater Unionidae was constructed based on mitochondrial COI sequences. The phylogenetic trees were constructed by the minimum evolution (ME) method, in which the 13 species were divided into three groups. The first group comprised Solenaia oleivora, Solenaia carinatus, Solenaia rivularis and Lamprotula caveata. The second group included Anodonta arcaeformis, Anodonta woodiana elliptica and Anodonta woodiana pacifica. While Lanceolaria gladiola, Lanceolaria grayana, Unio douglasiae, Lamprotula tortuosa, Acuticosta chinensis and Cuneopsis heudei made up the third group. Phylogenetic analysis of the genus Solenaia shows that the Chinese endemic species Solenaia comprise not three species as previously supposed, but four species, one of which has not yet been formally brought forward and described. COI sequences can provide useful information for phylogenetic studies in the Unionidae, and has important implications for these animals’ conservation, especially for those considered to be endangered.
Key words. Unionidae, freshwater, mussels, Solenaia, mitochondrial DNA, phylogeny
Date of publication. August 2011
2011-40508
Giambattista Bello
Abstract. In the last quarter of a century, two different specific names have been used in the scientific literature to indicate the same sepioline species, that is Sepietta obscura Naef 1916 and Sepietta petersi (Steenstrup 1887). The original description of the latter binomen was reviewed, as well as other relevant literature, and S. petersii was shown to be an invalid nominal species according to the rules of the International Code of Zoological Nomenclature. The nomenclatural revision of the genus Sepietta and the species contained in it was also carried out.
Key words. Cephalopoda, Sepiolidae, nomenclature, species validity
Date of publication. August 2011
2011-40509
The genus Nemocardium Meek 1876 in the Plio-Pleistocene of Italy (Bivalvia, Cardiidae)
Rafael La Perna & Mauro D’Abramo
Abstract A revision of Nemocardium Meek 1876 from the Mediterranean Plio-Pleistocene has led to the recognition of two species, Nemocardium (N.) cyprium (Brocchi 1814) and Nemocardium (N.) italicum nom. nov. Both species are poorly known and with a complex history of misidentifications. Brocchi’s holotype of Venus cypria, from the Early Pliocene deposits of Siena (Italy), is the only specimen of Nemocardium (N.) cyprium so far known. Nemocardium (N.) italicum occurs in fine-grained deposits, ranging from the Early Pliocene to the Early Pleistocene. Both in the old and in the modern literature, this species has been misidentified as Cardium striatulum Brocchi 1814, which is synonym of Laevicardium crassum (Gmelin 1791). Nemocardium was notably diverse in the Eocene and Oligocene of England, France and Italy. The occurrence of Nemocardium in the Neogene-Pleistocene of Europe is a case of biogeographic disjunction, due to the closure of the eastern seaway to the Indo-Pacific in the late Early Miocene. As a consequence of the climatic cooling through the Cenozoic and Quaternary, Nemocardium underwent a dramatic drop in diversity. Its persistence in the Mediterranean till the Early Pleistocene, with Nemocardium (N.) italicum, was probably due to favourable climatic conditions in this basin. Nemocardium (N.) bechei (Reeve 1847) seems to be the sole living species, mainly distributed in the tropical waters of the Indo-Pacific.
Key words. Cardiidae, Nemocardium, systematics, Plio-Pleistocene, Italy
Date of publication. August 2011
2011-40510
A second British site for Coracuta obliquata (Chaster 1897) (Mollusca, Bivalvia) in the southern North Sea [Short Communication]
A.L. Colcombe & J.M. Hill
Date of publication. August 2011
2011-40511
On the nomenclatural status of Nassa elabrata Doderlein 1864 (Mollusca, Gastropoda, Nassariidae) [Short Communication]
G. Manganelli, A. Benocci and V. Spadini
Date of publication. August 2011
2011-40512
One less Achatina in Kenya: A. yalaensis Germain and Oreohomorus connollyi (Odhner) (Pulmonata: Subulinidae) [Short Communication]
B. Rowson
Date of publication. August 2011
2011-40513
Five new introduced snail species (Mollusca: Gastropoda) in Nepal [Short Communication]
Atanas Irikov & Dimitar Bechev
Date of publication. August 2011