中国沟颈螺属一新种记述(腹足纲:柄眼目:艾纳螺科)

记述中国沟颈螺属１１种,其中包括１新种,即芒康沟颈螺Ｈｏｌｃａｕｃｈｅｎ ｍａｒｋａｍｅｒｓｉｓ Ｃｈｅｎ ｅｔ Ｚｈａｎｇ,ｓｐ．ｎｏｖ．,编制了分种检索表,对新种进行了描述,并与近似种进行了比较。     

Molecular phylogeny of euthyneura (mollusca: gastropoda)

A new phylogenetic hypothesis for Euthyneura is proposed based on the analysis of primary sequence data (mitochondrial cox1, trnV, rrnL, trnL(cun), trnA, trnP, nad6, and nad5 genes) and the phylogenetic utility of two rare genomic changes (the relative position of the mitochondrial trnP gene, and an insertion/deletion event in a conserved region of the mitochondrial Cox1 protein) is addressed. Both sources of phylogenetic information clearly rejected the monophyly of pulmonates, a group of gastropods well supported so far by morphological evidence. The marine basommatophoran pulmonate Siphonaria was placed within opisthobranchs and shared with them the insertion of a Glycine in the Cox 1 protein. The marine systellommatophoran pulmonate Onchidella was recovered at the base of the opisthobranch + Siphonaria clade. Opisthobranchs, Siphonaria, and Onchidella shared the relative position of the mitochondrial trnP gene between the mitochondrial trnA and nad6 genes. The land snails and slugs (stylommatophoran pulmonates) were recovered as an early split in the phylogeny of advanced gastropods. The monophyly of the Euthyneura (Opisthobranchia + Pulmonata) was rejected by the inclusion of the heterostrophan Pyramidella.     

Breeding system and population genetic structure in philomycid slugs (Mollusca: Pulmonata)

Four species of philomycid slugs were collected at 13 sites in Tennessee and one site in Virginia. A total of 361 individuals were examined electrophoretically at 11 allozyme loci. Outcrossing was the primary breeding in all populations of all four species. Genetic similarities among demes, among species and among genera are similar to values obtained in studies of other animals with similar vagility and demography and are in good agreement with systematics based on morphological characters. In the species examined in greatest detail, Philomycus carolinianus , there was substantial genetic differentiation among demes. This differentiation appears to result from genetic drift and restricted gene flow. Genetic similarity between P. carolinianus demes did not correlate with the geographic distance between demes and hierarchical F-statistic analysis showed more than half of the differentiation among demes to result from differentiation at the smallest geographic scale. The Tennessee River system also appears to be a major barrier to gene flow among the P. carolinianus demes sampled.     

Satsuma jinlunensis— a new species from Taiwan (Stylommatophora: Camaenidae)

A new species of camaenid land snail, Satsuma jinlunensis n. sp., from southeastern Taiwan is established. This species inhabits the lowland forests with a narrow geographical distribution insofar as we know. The species is characterised by having a sinistral shell, a rounded periphery, an oblique columellar lip joining the basal lip smoothly, an open umbilicus, a coiled flagellum, an absent or weakly developed penial caecum, a hemispherical verge internally, and a pedunculus of the bursa copulatrix expanded medially. The new species is distinguishable from congeners by a combination of its sinistral and conical shell, and coiling of the flagellum and part of the epiphallus. The characteristics of male genitalia and species biodiversity of terrestrial snails in southern Taiwan are discussed.

http://zoobank.org/urn:lsid:zoobank.org:pub:96F3118C-09B9-4ED4-AAB7-2DBEE978459F     

Arnhemtrachia ramingining: a new genus and species of land snail from Arnhem Land,Australia (Stylommatophora: Camaenidae)

The new, monotypic camaenid genus Arnhemtrachia is described for the new species Arnhemtrachia ramingining from Ramingining, Arnhem Land, Northern Territory, Australia with additional records from the Gove Peninsula in eastern Arnhem Land. This camaenid is characterised by a combination of distinct morphological features, such as a small, discoidal, keeled shell with regular axial ribs, open umbilicus and simple, rounded aperture as well as a reproductive system with a long epiphallus possessing a long flagellum and absence of a penial sheath, with a flap on the penial wall which transverses longitudinal pilasters, and a long, simple bursa copulatrix. Based on comparative morphology, Arnhemtrachia reveals affinities with Trozena morata Iredale, 1838 from NE Queensland.     

Haemocyte apoptosis as a general cellular immune response of the snail, <Emphasis Type="BoldItalic">Lymnaea stagnalis</Emphasis>, to a toxicant

The effects of a xenobiotic on the circulating haemocytes of Lymnaea stagnalis were investigated after short-term (24 h, 96 h) and long-term (504 h) exposure of snails to environmental concentrations. Fomesafen, a pro-oxidant generator led to the activation of the haemocyte apoptotic program by promoting reactive oxygen species (ROS). Cells entering apoptosis underwent a series of events, both on the plasma membrane and in the mitochondria; these events were quantified by flow cytofluorometry. The data showed a loss of mitochondrial transmembrane potential (Δψm), which was dose-dependent and time-dependent and related to an increased release of superoxide anions. The phosphatidylserine that was exposed at the outer plasma membrane was not related to the disruption of either ROS or Δψm but was strongly correlated with the haemocyte concentration (total haemocyte count). This cascade of apoptotic processes occurred in a dose-independent manner and was not strengthened over time. The increase of circulating haemocytes depended upon the life span of the cells and might have reflected either facilitated cell turn-over or the accompanying presence of haemocytes phagocytosing apoptotic cells.     

中国杂斑螺属一新种记述(肺螺亚纲,柄眼目,艾纳螺科)

记述采自甘肃省陆生贝类1新种,即宕昌杂斑螺Subzebrinus dangchangensis 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。     

中国沟颈螺属研究及一新种记述(肺螺亚纲,柄眼目,艾纳螺科)

记述中国沟颈螺属12种,其中包括1新种,即康种检索表,对新种进行了描述,并与近似种进行了比较。模定沟颈螺Holcuuchern kangdingensis sp.nov,同时编制了分式标本保存于中国科学院动物研究所。     

The cephalic sensory organ in veliger larvae of pulmonates (Gastropoda: Mollusca).

The apical area of larvae of four primitive pulmonate species was investigated by means of serial ultrathin and light microscope sections. Cephalic sensory organs (CSOs) were found in the larvae of Onchidium cf. branchiferum (Onchidiidae) and Laemodonta octanfracta (Ellobiidae), while no trace of the organ was present in the larvae of Ovatella myosotis (Ellobiidae) or Williamia radiata (Siphonariidae). TEM investigation revealed very similar CSOs in O. cf. branchiferum and L. octanfracta, with characteristic putative sensory cell types: ampullary cells with an internal ampulla containing densely packed cilia, para-ampullary cells with external cilia parallel to the surface, and ciliary tuft cells, bearing short ciliary tufts. The epithelium covering the organ has a thick microvillar border with microvilli laterally bearing a pair of electron-dense accumulations and a glycocalyx with interspersed flat plaque-like elements. While homologues of all major elements of the CSO can be found in other gastropod taxa, for example caenogastropods and opisthobranchs, the homology of the ampullary cell with similar cells in nongastropods appears unlikely. The CSO of L. octanfracta is associated with an additional structure, an epithelial external protrusion, lying ventral to the CSO. The absence of the organ in W. radiata weakens hypotheses on the organ's function of examining settlement conditions and velar control.     

Rediscovery of Ellobium scheepmakeri (Petit De La Saussaye, 1850) (Mollusca: Gastropoda: Ellobiidae), a rare ellobiid in Bukit Belimbing mangrove forest,Peninsular Malaysia

The ellobiid Ellobium scheepmakeri (Petit de la Saussaye, 1850) is reported from the banks of the Selangor River estuary, 57 years after it was first collected in Peninsular Malaysia. It was found in abundance under logs in the dryland mangrove forest of a dominantly Nypa swamp at the upper reaches of the Kuala Selangor estuary where sediment pore water salinity was recorded at 6–7 ppt.