Abstract
A new muraenid, Gymnothorax ypsilon, is described from seven specimens from Japan and four from the Hawaiian Islands. It has about 30 narrow dark bars on the body, some of which are Y-shaped on most specimens, a uniformly colored head, an anal fin with a white margin, and 141-153 vertebrae. It differs from G. pikei, its most similar species, by a white margin of the anal fin.
