On species composition of molluscs from the genus Hydrobia (Gastropoda, Prosobranchia) in the White Sea.

A.M.Gorbushin, Zoologichesky Zhurnal, 1992, vol.71, N 9, pp.47-56 [In Russian; English summary].

Abstract: It is confirmed the specific distinctness and defined the specific identification for the Hydrobia sp., a Hydrobia form which differs by several features from Hydrobia ulvae Pennant, 1777, the single previously known representative of this genus in the White Sea. There were found differences between two Hydrobia species in the microbiotopic distribution on the littoral zone and in the parasitofauna composition in the sympatric groups. The studied molluscs differ in body and shell coloration as well as in size and shape of the penis. A veliger - stage is missing in the life cycle of the Hydrobia sp. There were revealed no reliable diagnostic characters in the radula structures. According a number of features the Hydrobia sp. is certainly identified as Hydrobia ventrosa Montagu, 1803.