OKINAWAN
OPISTHOBRANCH OF THE WEEK

Opisthobranch of the Week Data

Taxonomy:

        Hypselodoris whitei is considered to be rare on Okinawa as I have collected a total of seven individuals over a period of many years of diving here. The animal was found crawling in the open during a daytime SCUBA excursion amid miscellaneous stony corals in an area of spur and groove formations of a living Porites coral reef. In addition to Okinawa, the species is also known from eastern Australia, Indonesia, the Maldives, Marshall Islands, New Caledonia, Papua New Guinea, and the Philippines.

        Gosliner and Johnson (1999) point out the taxonomic confusion surrounding Hypselodoris whitei and a closely related species, H. maridadilus. Among several field-observable characteristics separating the two species, the presence of a distinctively obvious white rhinophoral tip in H. whitei separates the two; the red rhinophores of H. maridadilus may possess white tips, but they are considerably less obvious than in the case with that of H. whitei. H. maridadilus has been reported as being found in Japan (Baba, 1953, as Glossodoris hilaris), but not yet found in Okinawan waters.

        The featured animal is one of twelve described species of Hypselodoris found in Okinawan waters. The twelve species identified to date (February, 2005) are: