New data on the valvatiform-shelled Hydrobiidae (Caenogastropoda, Truncatelloidea) from southern Greece.

The minute valvatiform-shelled Hydrobiidae are less studied than other hydrobiid gastropods. In this paper, new data on these snails are presented, which have been collected at twelve springs in southern Greece: one in Boeotia, one on Evvoia Island, and ten on the Peloponnese Peninsula. Mitochondrial cytochrome oxidase subunit I (COI) and nuclear histone (H3) have been used to confirm the determinations and infer the relationships of the studied gastropods. They represent the genera Daphniola, Graecoarganiella and Isimerope. New localities, expanding the known geographic ranges, have been presented for Daphniolahadei and Daphniolalouisi. A species of Daphniola found at two localities has been identified as a species new to science, and its description, including the shell, penis, and female reproductive organs is given. Possible relationships between Graecoarganiella and Isimerope are discussed; their representatives are possibly new species. At one locality a single specimen likely represents a new genus: it was found to be most closely related with Islamia, but genetically (p-distance) too distant to be congeneric with Islamia.