First record of a bathyal bryozoan fauna from the Sea of Japan

Abstract

One cyclostome, one ctenostome and nine cheilostome bryozoan species, collected during Cruise 51 of the R.V. Akademik M.A. Lavrentyev in the northern part of the Sea of Japan at five stations, ranging from 455 to 2481m in depth, comprise the first records of bathyal bryozoans from this sea. Among these are six species newly recorded from the bathyal zone, and eight species displaying their deepest records. Two bryozoans, Bugula pacifica nana and Scrupocellaria scabra var. praenulata forma orientalis, are elevated to full species status, respectively Bugula nana and Scrupocellaria orientalis. The records of Scrupocellaria orientalis, Microporina okadai and Klugeflustra kishikaensis are the first for the Sea of Japan, with Eucratea arctica recorded for the first time from the northern Pacific. The predominance of erect rooted, branching and foliaceous colonies is strongly correlated with the distribution of soft sediments in the collecting area, possibly accounting for the low overall species diversity and abundance.