Opisthobranch of the Week Data
I've not personally seen Hypselodoris zephyra here in the waters of Okinawa's main island. Atsushi Ono has seen only two animals as of February, 2005 and of course considers the species to be rare in the Keramas * Atsushi reports (pers. comm.) finding the above featured animal on dead coral associated with a rocky substrate. Also, I've added a second page with an image of an additional animal photographed in the Keramas by Atsushi.
The following description of external morphology is taken from Gosliner & Johnson (1999):
The living animals are 6-25 mm in length. The animals are elongate, with the mantle margin forming a very small rim overhanging the side of the foot. The general body colour of H. zephyra is white. The mantle is marked by a series of black lines which run parallel to each other and to the body axis. At least two or three pair of lines on either side of the mantle midline converge to make an hourglass like pattern with the lines diverging again around the rhinophores and the gills. One black line almost completely encircles the mantle, but is interrupted once at the posterior edge and twice anteriorly. Yellow patches are scattered throughout the black lines. These patches and lines are absent from the area immediately surrounding the gills and the rhinophores. There are a few grey to purple patches on the mantle, most noticeably on the posterior edge, to the outside of the rhinophores and at the front of the head region. The foot has a thick purple line around the margin and a distinctive black line down the middle of the dorsum. The rhinophores are dark orange with white tips. Immediately behind the rhinophores is an area of translucence though which the eyes are visible. The 6-7 simply pinnate gills are the same dark orange colour as the rhinophores, but are darker along the rachis.
The above featured animal is one of thirteen described species of Hypselodoris found in Okinawan waters. The thirteen species identified to date (July, 2011) are:
* Keramas = the Kerama Islands Group, located 30 ~ 40 kilometers west of the Okinawa capitol, Naha.