A taxonomic position of Armenian endemic freshwater snails of the genus Shadinia Akramowski, 1976 (Caenogastropoda: Hydrobiidae): combining morphological and molecular evidence

Abstract

ABSTRACTAccording to analyses of anatomical data and nucleotide sequences of three genes (16S, 18S rDNA and CO 1 mtDNA), the Armenian endemic genus Shadinia Akramowski, 1976 should be considered as a separate subfamily, Shadiniinae of Hydrobiidae Stimpson, 1865. A combination of genetic resemblance and similarity in conchology, morphology of radula, male and female anatomy (except some details) assures us of the close relationship of Shadinia and the genera Persipyrgula and Intermaria recently described from riverine waters of Iran. We provisionally assign these two genera to the new subfamily, which also includes the genus Nicolaia, established in 2015 for small hydrobiids from the Kasach River (Armenia). The latter genus has not yet been studied genetically, but morphological evidence leads us to consider it as compatible with Persipyrgula and Intermaria. All three genera differ significantly from the genus Shadinia in only one respect: females of these snails have one seminal receptacle, while those of Shadinia have two. The subfamily Shadiniinae is a sister group to Pyrgulinae; the former differs morphologically from the latter in possessing a pigmented nervous system and odontophore, presence of basal cusps on the central tooth of the radula and a black pigmented coiled oviduct without the widening that characterises most of the Pyrgulinae.http://zoobank.org/urn:lsid:zoobank.org:pub:3009CB4E-EE5B-44BE-B8E4-497B5CB3BE5D