Revision of the Genus Margaritifera (Bivalvia: Margaritiferidae) of Japan, with Description of a New Species

Abstract

A new margaritiferid species, Margaritifera togakushiensis, is described from the Sakasa River at Togakushi, Nagano Prefecture, Honshu and the Furebetsu River at Furano City, Hokkaido, Japan. The anterior margin of the shell is semicircular and the shape of the adductor muscle scar is acute auriform, versus semi-elliptical and round auriform in M. laevis. The host fish of the glochidia is also different: Salvelinus leucomaenis for M. togakushiensis and Onchorhynchus masou for M. laevis.