Opisthobranch of the Week Data
Taringa halgerda is considered to be very rare in okinawan waters as neither I nor Atsushi Ono have previously seen it. Atsushi reports (pers. comm.) seeing/collecting only the above single individual in the Keramas * and as far as I can determine this is the first time this attractive little discodoridid is reported from okinawan waters. This charming little animal was found by Atsushi between small stones and dead coral in 18m of water. There are quite a few photographs of Taringa halgerda found on the web, all from the Philippines, Malaysia and Indonesia. As an example Mike miller has a excellent photograph of T. halgerda on the Slug Site from the PI with a short discussion by Dave Behrens.
With Atsushi's above photograph and specimen this is perhaps the first time the species has been reported from anywhere in Japanese waters.
The following description of external morphology is taken from the Gosliner and Behrens (1998) publication:
EXTERNAL MORPHOLOGY. - Preserved animals are 22-33 mm in length. The living animals are white with low, flat, yellow tubercles. The tubercles are digitate, with short, round papillae extending from their posterior surface. The largest are capitate with a narrow, short base. These are found medially on the dorsum. The anterior end of the foot is bilabiate and notched. On either side of the head is a long, digitiform tentacle. The branchial plume, comprised of six sparsely branched, multipinnate gill branches, is large, nearly twice the width of the body in diameter. The anus is situated within the circle formed by the gill branches. The size and shape of the gill represent the basis for considering this species "Halgerda-like" in its appearance. A black line extends up the edge of each gill branch. The black, perfoliate rhinophores bear about 17-18 lamellae.
* Keramas = the Kerama Islands Group, located 30 ~ 40 kilometers west of the Okinawa capitol, Naha.