OKINAWAN
OPISTHOBRANCH OF THE WEEK

Opisthobranch of the Week Data

Taxonomy:

        Hypselodoris bollandi, recently described by Gosliner & Johnson (1999), is considered to be very rare here on Okinawa as I have collected only two specimens; a third uncollected individual was photographed in 40ft of water on the 17^th of March, 1984 at Tengan Pier, however the size was not recorded. The above featured animal had been misidentified by myself as a previous featured animal as Risbecia pulchella, which is very similar to Hypselodoris bollandi. The two species can be discriminated from each other by the following external characteristics: H. bollandi has orange-red rhinophores and gills which are relatively static; Risbecia pulchella has dark blue rhinophores and gills which are in constant motion.

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

Literature Cited: