Redescription of a rare mysid Nipponomysis surugensis (Murano, 1977) (Crustacea, Mysida, Mysidae) based on specimens from the Seto Inland Sea, Japan

Nipponomysis surugensis (Murano, 1977) (Crustacea, Mysida, Mysidae) was first reported on the basis of specimens collected from Suruga Bay, central Japan. No further collections have been made to date since the original record. Specimens recently found in the Seto Inland Sea, western Japan, were referred to N. surugensis. Our study re- vealed that N. surugensis is very remarkable among the members of Nipponomysis Takahashi & Murano, 1986 by having four-segmented carpo-propodi on the third to eighth thoracopodal endopods, as opposed to three segments in the remaining species. This rare species is redescribed based on newly-obtained specimens. An updated key to the species of Nipponomysis is provided.