The Bivalve Divariscintilla toyohiwakensis n. sp. (Heterodonta: Galeommatidae) from Japan, a Commensal with a Mantis Shrimp

摘要

We describe the morphology of a new species of the bivalve family Galeommatidae, Divariscintilla toyohiwakensis n. sp., which lives in the burrows of the mantis shrimp Acanthosquilla acanthocarpus at Oshinden, Nakatsu, Oita Prefecture, Kyushu, Japan.An unpaired median tentacle and three paired tentacles issue from the mid-mantle fold, which partially covers the shell.A single flower-like organ originates on the anterior surface of the visceral mass. A byssal adhesive gland is observed on the most posterior part of the foot. This is the first record of the genus in Japan and the North Pacific Ocean.