OKINAWAN
OPISTHOBRANCH OF THE WEEK

Elysia lobata (Gould, 1852) 11mm

Opisthobranch of the Week Data

Taxonomy:

Frequency on Okinawa:
Collection Data:
[brackets indicate range for all Okinawa-collected specimens of the species]


Species Account:

        Elysia lobata is considered to be very rare on Okinawa as I have seen and collected only two individuals (11mm & 8mm). The nearest match I can make to this attractive little Okinawan plakobranchid, from the published literature, is one found in Suzuki (2000, p.46, #56), who identifies it as E. rufescens and appears to be very similar to the Okinawan material. The Suzuki image is possibly misidentified and is likely E. lobata. I've included an image of the only other specimen found here to date; an 8mm animal from 5ft, collected near the southern end of the main island of Okinawa.
        Note: This featured animal was previously misidentified by RFB as E. rufescens. Both Cory Pitman and Terry Gosliner kindly pointed out the error and the earlier featured animal has now been changed to E. lobata.

        I've taken the following species information from Kay (1979), based on her description of Hawaiian material:

        Animal : parapodia carried upright, with two or three undulations; rhinophores long and slender, grooved their entire length and usually curving anterolaterally; skin smooth or with glandular pustules, occasionally with villi. Color : pale blue-green, the surfaces of the body and parapodia crowded with black and white spots, occasionally with black ocelli; parapodia margined with pink, sometimes edged with yellow; rhinophores pink, tipped with blue.
        This is the commonest species of elysiid in Hawaiian waters and one to ten animals can be collected monthly throughout the year. These gastropods are found under rocks on beaches where there is considerable surf action, and in shallow waters shoreward of fringing reefs.
        E. lobata was described from the Hawaiian Islands and is also recorded from the Marshall Islands (Marcus, 1965).

Literature Cited:


Page Date: 20 Aug '01
Page Modification Date: 09 Mar '05
Digitally manipulated photo
Copyright © 2005 Robert F. Bolland