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Information × Registration Number 0214U000047, 0112U003675 , R & D reports Title Reconstruction of key philogenetic stages of superfamily Viviparoidea (Gastropoda: Caenogastropoda) and closely related taxa: syntesis of morphological, molecular-genetic and paleontological data popup.stage_title Head Anistratenko Vitaliy, Registration Date 13-01-2014 Organization Schmalhausen Institute of Zoology popup.description2 Distribution of molluscs of the family Viviparidae is considered as a whole for Eurasia for the first time: actual geographic ranges for viviparids in the region are established, the biogeographical changes which have occurred for last 40 years are marked. At the background of general stability in Eurasia there are fluctuations of geographic ranges of palearctic genera within the basins of some rivers. For the first time it is established, that Northern Azov Sea shore represents a geographical "lacuna" where representatives of viviparid family are absent. The basic morphological traits of the viviparids radula variability for Viviparus and Contectiana in ontogenetic aspect were in details investigated. For the first time the rachidian tooth abnormalities were registered: secondary splitting of the lateral denticles into two or more (1), their merging (2), changes in shape (3) and dimensions (4), finally, increasing or decreasing in the number of denticles (5). Uninterrupted (though also non-uniform) growth of juvenile snails during whole year confirms the absence of winter diapause in life cycle of viviparids. The sufficient data for reconstruction of the basic trends of phylogeny of Viviparoidea are obtained. The main direction of their morphogenesis is determining by reduction of the absolute sizes of molluscs shell (1) and loss of a sculpture (2). The opportunity of partial reversibility or even cyclicity of viviparids morphogenesis and also formations of gigantism and occurrence of talassoid forms living in modern lakes of Southeast Asia (Margarya, Torotaia, Celetaia) is shown. The complex approach (using of the protoconch and teleoconch morphology, structures of a shell wall, the structure of radula and reproductive system) appeared effective for verification of systematic, and also for clearing of taxonomy of this group of molluscs. Product Description popup.authors Аністратенко В.В. Аністратенко О.Ю. Дегтяренко О.В. Рябцева Ю.С. popup.nrat_date 2020-04-02 Close