OKINAWAN
OPISTHOBRANCH OF THE WEEK

Opisthobranch of the Week Data

Taxonomy:

        Volvatella ayakii is considered to be very rare in Okinawan waters; I've not personally seen this attractive little volvatellid here in the waters of Okinawa's main island and Atsushi mentions (pers. comm.) seeing only the above single uncollected individual in the Keramas.* Atsushi reports that it was found amid seaweed associated with a mooring chain associated with a buoy.

        I've previously featured one other described species of Volvatella on these pages, V. angeliniana, from Okinawa's main island. In addition to the two described species from Okinawan waters (V. angeliniana and V. ayakii), I've also found an undescribed(?) green-shelled animal and a brown-shelled animal. Ichikawa (1993) found two additional Volvatella here: 1) Volvatella viridis, described by Hamatani (1976) from Japan, and 2), an undescribed species, but different from the unknown green-shelled specimens I've collected.

        Both Bill Rudman (2002) and Jun Imamoto (2004) have a series of excellent photographs of Volvatella ayakii posted on their sites.

Literature Cited:

        * Keramas = the Kerama Islands Group, located 30 ~ 40 kilometers west of the Okinawa capitol, Naha.