Opisthobranch of the Week Data
The above featured little animal, Piseinotecus sp. 1, was previous featured on these pages as "Unknown Opisthobranch #1" and I now have at least its generic placement. It's considered to be very rare in the waters of Okinawa's main island as it's the only specimen I've seen or collected. Piseinotecus sp. 1 was collected during a mid-morning SCUBA dive from an area of mixed sand and coral rubble from 195ft. I've also added a second page with three additional images of the same animal.
There is a very similar appearing animal in Gosliner, et al, 2008 (Piseinotecus sp. 1, p. 353), as well as a series of similar animals seen on several on-line sources (Mike Miller's Slug Site, Kwajalein Underwater and Nudi Pixel).
The following information is taken from Gosliner, et al, 2008 (Piseinotecus sp. 1, p. 353):
Identification: The systematic placement of this species remains uncertain. Body translucent white with opaque white along the edges of the notum. Yellow pigment forming a continuous line along the undulating notal margin. Black viscera visible through the notum. Most of the smooth rhinophores and oral tentacles yellow.
Natural History: Found under coral rubble in 7-8 m of water on barrier reefs.
Size: 12 mm
Distribution: Known from the western Pacific of Australia, Papua New Guinea, the Philippines, and southern Japan.