OKINAWAN
OPISTHOBRANCH OF THE WEEK

Phyllodesmium sp. 2 (10mm)
Photo by Atsushi Ono

Opisthobranch of the Week Data

Taxonomy:

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


Species Account:

        As of the current date I've not personally seen representatives of the above attractive little facelinid here in the waters of Okinawa's main island. Phyllodesmium sp. 2 is considered by Atsushi Ono to be rare in waters of the Keramas* and he reports (pers. comm.) seeing over ten individuals in the Keramas, but has collected only three specimens. Atsushi goes on to say that the above animal was found between dead coral and rock. The above image was taken by Atsushi and is used here with his kind permission. I've added an additional image of Phyllodesmium sp. 2, also furnished by Atsushi.

        Phyllodesmium sp. 2 would appear identical to an animal shown and described in Cobb & Willan (2006, p. 293). The following description of the Cobb & Willan animal (southern Queensland) is a close match to the Okinawa animals, and is as follows:

This small nudibranch is recognised by the long slender translucent body, and the long rounded orange-tipped cerata. The large yellow spots outlined in white on the dorsal midline resemble a row of eggs. The translucent cerata are arranged in small vertical groups with the longest ceras uppermost. There is a prominent thick brown digestive diverticulum running through the centre of each ceras. The tip of each ceras is opaque white with a pale orange ring. The rhinophores are smooth and orange with a white tip. The oral tentacles are long and rounded, and pale orange to translucent white.

        This is one of several undescribed species of Phyllodesmium species known from Okinawan waters; previously I've featured on these pages the following described and undescribed (or at least unknown by myself) Phyllodesmium species:

Literature Cited:


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


Page Date: 17 Dec '07
Page Modification Date: 01 May '15
Digitally manipulated photo
Copyright © 2015 Robert F. Bolland