Four New Mytilid Mussels Associated with Deepsea Chemosynthetic Communities around Japan

Abstract

Four new species of Bathymodiolus, B. platifrons n. sp., B. japonicus n. sp., B. aduloides n. sp., and B. septemdierum n. sp., are described from materials collected at hydrothermal vent and cold seep sites around Japan. These deepsea mussels have extremely thick and large ctenidia with long demibranchs. In addition, these new species have no extreme mantle fusion which restricts the incurrent aperture to a short byssal-pedal gape in the ventral mid-region, the typical feature of the genus Bathymodiolus Kenk and Wilson, 1985.