Species validity of Astarte inaequilatera (Filatova in Scarlato, 1981) and comments on the Astartidae (Bivalvia) of the Russian Far Eastern seas

The validity of Astarte inaequilatera (Filatova in Scarlato, 1981) (Bivalvia: Astartidae) is substantiated. It is a Pacific, widely-distributed boreal species, earlier synonymized with the subtropical, Japanese- Korean Astarte hakodatensis Yokoyama, 1920. A. hakodatensis differs from A. inaequilatera by the crenulated inner ventral margin of the shell, lack of undulating commarginal ribs (only growth marks are present), radial threads, and strongly produced anterior margin. The shell of the former is thicker and darker, with a dark brown periostracum. A. inaequilatera usually has a yellow-brownish to olivaceous periostracum. A. hakodatensis differs from Astarte montagui (Dillwyn, 1817) by the crenulation of the inner margin and a smaller size. Detailed synonymies of both species are compiled for the first time. Taxonomic and faunal comments on the Astartidae of the Russian Far Eastern seas are provided.