OKINAWAN
OPISTHOBRANCH OF THE WEEK

Aplysia parvula Guilding in Mörch, 1863 (30mm)

Opisthobranch of the Week Data

Taxonomy:

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


Species Account:

        Aplysia parvula is considered to be uncommon on Okinawa, although I've only collected seven individuals as of early September, 2000, I've photographed several others and have certainly seen, but neither photographed nor collected, an additional dozen or so. Baba (1949) was the first to report on the occurrence of the species in Japan and describes it as being "Common almost everywhere on the Pacific coasts of Japan." The species is considered to be both circumtropical and circumtemperate in distribution.

        This is the smallest of the Aplysia species, with its maximum size probably less than 60mm. Most but not all individuals are found with numerous white body speckles. The parapodia, foot, as well as the rhinophoral tips and and oral tentacles have a relatively thin black emarginated line.

        The above featured animal is unusual in its bright red color and this particular color variation is the only one I've seen here. There is a similarly pigmented animal on page 22 in Keiu (2000), photographed at Izu Oceanic Park in mainland Japan. I've posted an additional page showing three of the more common occurring color variations.

Literature Cited:


Page Date: 04 Sep '00
Page Modification Date: 04 Sep '00
Digitally manipulated photo
Copyright © 2000 Robert F. Bolland