Opisthobranch of the Week Data
I've not personally seen Siphopteron sp. 2 in the waters of Okinawa's main island, however Atsushi Ono mentions seeing an excess of ten animals in the Keramas * and considers it to be uncommon there. Atsushi's photograph was taken from the waters of Zamami Island on the 27th of July, 2009 and reports finding it on a sandy bottom environment (pers. comm.). Atsushi's photographs are used here with his kind permission.
I've added a second page with another of Atsushi's animals illustrating a different colored individual. Bill Rudman's Sea Slug Forum has several different colored individuals of Siphopteron sp. 2 (as Siphopteron sp. 5) similar to those of Atsushi's animals.
The following description of Siphopteron sp. 2 (as Siphopteron sp. 5) is taken from Rudman, W.B., 2004 (Jan 16):
The parapodia & visceral hump is dark brown with scattered white or translucent clear patches. The edge of the parapodia have many opaque white patches. The headshield is translucent greyish with some brown patching & mottling. The gills are black. In the photographed specimen the parapodia have distinctly reddish brown patches. There are a pair of short white triangular papillae on the posterior edge of visceral hump. They can swim when disturbed.
There are to date the following nine described species of Siphopteron known from Okinawan waters, as well as several undescribed species.
* Keramas = the Kerama Islands Group, located 30 ~ 40 kilometers west of the Okinawa capitol, Naha.