Redescription of Sarsia japonica (Nagao) (Hydrozoa : Corynidae) from Hokkaido, Japan

Abstract

Sarsia japonica (Nagao) is redescribed and illustrated, based on I female and 6 male colonies collected from Muroran (a new locality) and Akkeshi (the type locality), Hokkaido, Japan. Previously undescribed character states of both the hydroid and the laboratory-reared medusa are noted and the substrata occupied by this species and its geographical distribution are summarized. Sarsia japonica is judged to be a distinct species, and the characteristics that distinguish its hydroid and medusa from those of its closest congener, S. producta (Wright), are pointed out.