Molecular phylogeny reveals high diversity and endemism in the limestone karst-restricted land snail genus Sophina Benson, 1859 from Myanmar (Eupulmonata: Helicarionidae), with description of four new species

Sophina is a poorly known and neglected genus due to the inaccessibility of the Salween Basin, Southern Myanmar. Taxonomic status, distribution, and phylogeny are being revised based on an integrative analysis of genitalia, radula, and molecular data. Morphological variation in shells and genitalia, together with a phylogenetic tree from concatenated data of mitochondrial and nuclear genes, revealed the existence of ten species/subspecies. Penial morphology and genetic divergence were generally consistent and useful in delimiting species, while shell characters showed little overall taxonomic utility in some species. Taxonomic placement of the previous subspecies “bensoni” shows clear distinction in both genitalia and molecular evidence, and is currently recognized as a distinct species. The nominal species “S. schistostelis” and “S. calias” possess similar genitalia and shell morphology, and molecular evidence suggested that they are sister taxa representing geographically isolated populations. Four new species are additionally described herein as S. furfuracea n. sp., S. pisinna n. sp., S. salweenica n. sp., and S. tonywhitteni n. sp. based on both morphology and molecular evidence. Phylogenetic analyses supported monophyly of Sophina, and further a split into two principal clades. These two clades showed little difference in genitalia, but more clear differences in the umbilical area and allopatric distribution in upper and lower reaches of the Gyaing River. High genetic divergence was revealed and this coincided with remarkable degree of endemism and localization with a pattern of one outcrop for one lineage. These data highlight the importance of the Salween Basin's karst ecosystems as an evolutionary and endemic biodiversity hotspot, and indicate that a focus on conservation and management in this area is urgently required.     

中国喇叭螺属一新种(肺螺亚纲,柄眼目,虹蛹螺科)

记述采自贵州省陆生贝类1新种,修文贝喇叭螺Boysidia(Bensonella)xiuwenensis sp.nov.,文中对新种形态特征、栖息环境进行了描述,并对其相似种进行了分析和讨论。     

Historic data analysis reveals ambient temperature as a source of phenotypic variation in populations of the land snail Theba pisana

Pulmonate land snails are often polymorphic in their shell coloration pattern. To quantify the contribution of environmental parameters to the nondirectional change in phenotypic variation, we used a historic dataset on Theba pisana morph frequencies and climate data for statistical modelling. We found significant correlations of the degree of phenotypic diversity between juveniles and corresponding adult individuals within the same and the subsequent generation. Among climate parameters, the phenotypic diversity of adults correlated significantly and positively with the mean and maximum ambient temperatures in the winter and spring only. There was no correlation between high or low temperatures and the frequency of distinct morphs. Akaike's information criterion‐based model selection revealed the particular importance of only parental phenotypic diversity for next generation juvenile phenotypic diversity. By contrast, phenotypic diversity of the juveniles of the preceding year and the mean temperatures in winter and spring were important for the phenotypic diversity of adult snails. Approximately two‐thirds of the explicable variation in phenotypic diversity of adults was explained by inheritance and approximately one‐third was expained by ambient temperature. The present study shows that genetics and temperature interact to generate nondirectional changes in phenotypic variation within populations, which also can be reflected by changes in the phenotype of individuals. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109 , 241–256.     

Morphological study of muscular tissue collagen of wild and reared Cornu aspersum (Müller, 1774)

Muscular tissue collagen fibrils’ diameter and period of reared and wild snails (Cornu aspersum) were measured in order to investigate the role of nutrition on the collagen. Wild adult individuals were collected from Crete (Greece) and compared with adult individual snails reared under laboratory conditions fed a formulated diet. Transmission electron microscope and image analysis algorithms were used in the study. Statistically significant differences between the diameters of the collagen fibrils in the reared and the wild snails were found, and the D-period of the fibrils differed.     

The study of ontogenetic trajectory reveals the timing of reproductive events in Ancylus fluviatilis (Gastropoda: Planorbidae)

We analysed ontogenetic shape change in the planorbid limpet Ancylus fluviatilis (Müller, 1774) in two rivers in Southern Italy. We developed a new method to discriminate among different cohorts in Ancylus, based on principal component analysis. The method is useful when shape change during growth is allometric, as in our study model. We discovered that bivoltinism occurs in Ancylus in Southern Italy, contrary to previous accounts, which invariably describe A. fluviatilis as a semelparous and univoltine species, although acknowledging difficulty in discriminating among cohorts. The methods presented here may potentially help research in reproductive traits in many other mollusc populations where shape change during ontogeny is demonstrated to be allometric.     

贵州洞穴陆生贝类一新种(肺螺亚纲,柄眼目,烟管螺科)

记述了贵州省洞穴烟管螺科真管螺属1新种,即荔波真管螺Euphaedusa libonensis sp.nov．,标本采自贵州省荔波县董背洞内。对新种进行了详细描述,并与近似种做了比较。模式标本保存在中国科学院动物研究所无脊椎动物标本馆。     

中国金丝雀螺属研究及一新种记述(腹足纲,肺螺亚纲,柄眼目,艾纳螺科)

对我国金丝螺属9种和5亚种进行了整理和厘订,对德钦金丝螺新种进行了描述,并附有我国金丝螺属9种和5亚种的检索表。模式标本保存在中国科学院动物研究所无脊椎动物标本馆。     

广西砂螺属一新种(肺螺亚纲:柄眼目:虹蛹螺科)

作者于1999年在广西十万大山地区进行动物资源调查,获得一批陆生贝类,经鉴定得1新种,即扶隆砂螺Gastrocopta fulongensis sp.nov.。对新种进行详细的描述,并与近似种作了比较。     

中国陆生贝类一新种(肺螺亚纲:柄眼目:拟阿勇蛞蝓科)

作者于1981～1983年,参加中国科学院横断山综合考察队,赴云南地区进行考察,又于1993～1994年,赴滇南一带调查,获得陆生贝类标本一批,经整理鉴定,得拟阿勇蛤蝓科一新种：即云龙隐带螺Cryptozonayunlongensissp.nov.。本文对新种的形态特征作了详细描述,并对生殖系统进行了解剖,对颚片和齿舌作了电子显微镜观察,与其近似种古怪隐带螺Cryptozonaerratica（Heude,1882）进行了比较。     

中国烟管螺科二新种（肺螺亚纲：柄眼目）

本文记述采自陕西省陆生贝类二新种：陇县真管螺和镇安真管螺。文中对二新形态特征,栖息环境进行了描述,并对其相似种进行了分析和讨论。