OKINAWAN
OPISTHOBRANCH OF THE WEEK

Chromodoris decora (Pease, 1860) 14mm

Opisthobranch of the Week Data

Taxonomy:

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


Species Account:

        Chromodoris decora, a small attractive chromodorid, was originally described from Hawaii as Doris decora. The internal anatomy, however, dictates that it properly belongs in the genus Chromodoris. The following color description (partial) of the species is taken from Rudman (1986):

        The mantle is translucent with an orange band just in from the edge. There is a thin opaque white line which runs around the mantle, parallel to the edge, just encircling the rhinophore and gill pockets. Between this intense white line and the orange border the mantle is pigmented white but not so intensely as the thin line. From between the rhinophores a thin white line runs down the dorsal midline to midway where it bifurcates to form a loop around the gill pocket. Right at the edge the mantle is transparent, and the outer edge of the white mantle glands (masked further in by the orange pigment) appear as a series of white streaks or in some places a continuous white line. On the orange band is a line of small purple spots. Another row of much larger purple spots, diffuse at the edges, is found outside the thin white ring on the whitish submarginal band.

        C. decora is considered to be uncommon on Okinawa; I've collected ten specimens since the first was collected during early July, 1987, but others have been seen but neither photographed nor collected. The distinctive white Y-shaped pattern on the upper surface is unique to this Okinawan chromodorid and this effectively separates the species from other similar-appearing members of the family. The above featured animal was found during a daytime SCUBA dive in an area of strewn coral rubble at the reef forefront. The animal was collected from a small encrusting white poriferan, but it was not determined that the sponge was being used as prey.

Literature Cited:


Page Date: 21 Feb '00
Page Modification Date: 25 Mar '00
Digitally manipulated photo
Copyright © 2000 Robert F. Bolland