The first record of the family Parvaplustridae (Gastropoda, Heterobranchia) from hydrothermal vent fields of the Piip Volcano, Bering Sea with the description of a new species of the genus Parvaplustrum

Abstract

A new species, Parvaplustrum wareni sp. nov. (Parvaplustridae), collected in the area of the submarine Piip Volcano, the northwestern Bering Sea, at depths of 400–472 m, has been described on materials obtained during the research cruises #75 and #82 aboard the R/V Akademik M.A. Lavrentiev. This is the first record of the family in the Bering Sea. Parvaplustrum wareni sp. nov. is found around hydrothermal vents, where it forms aggregations with population densities of up to 6000–31 000 ind./m2. Parvaplustrum wareni sp. nov. differs from the other species of the genus by its globose shell, jaw morphology, and by the absence of spiral sculpture on the body whorl. In addition to the morphology, molecular data on mitochondrial (cytochrome c oxidase subunit I and 16S rRNA) and nuclear (histone H3 and 28S rRNA) markers were used. We assume that P. wareni sp. nov. feeds on bacterial mats, scooping them up with its petaliform radular teeth. The presence of bacteria-like filaments on gill lamellae suggests the possibility of an epibiotic association which needs further study. In addition to the Bering Sea, the range of this new species covers also the Hydrate Ridge, off Oregon (northeastern Pacific), where specimens were previously identified as P. cadieni.