July 16, 2003
From: Paul Sim
I noticed you did not have Polycera zosterae in your species list ... so here's one. It was (I think) the only time I've seen this in the 500 or so dives I have done (most in this area). I am led to understand it is not common and although the photo's are not stupendous (vis was under 10 feet and you can see some debris both on the animal and between the lens and the animal), I thought you might like to have them to at least start the listing. David Behrens book, Pacific Coast Nudibranchs has a listing for better details and photo.
Divesite: Cates Park, Indian Arm, Burrard Inlet, Vancouver, British Columbia, Canada
Depth: 25 feet., Water temp: 51 degrees Farenheit. Found on some red blade algae over a silt bottom. 27 May 2003.
Equipment: Nikonos-V 1:1 Fuji Superia 100
email@example.comSim, P., 2003 (Jul 16) Polycera zosterae from British Columbia. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/10392
Thanks for these photos. We are gradually getting photos of some of these rather small well-camouflaged species which are probably more common than we realise. Both your animal and the one in Dave Behren's book clearly show the white extra-branchial appendages which are characteristic of the genus Palio. Of more interest is that as Bleakney notes, the animal in Dave Behrens' photo is identical in shape and colour to the Atlantic species Palio nothus, which is found on both sides of the north Atlantic.
If your animal and Behrens' are the same species, it would be interesting to know just how much colour variation is found along the west coast of North America, for P. zosterae may turn out to be a Pacific population of Palio nothus.