Re: Pleurobranchaea californica from Santa Barbara, California

March 31, 2008
From: Mark W. Howe

Concerning message #17665:

The Orange County Floating Lab program, now Ocean Institute in Dana Point, California has been bringing these up from 20-30 fathom range on silty mud bottom for many years. I recall them commonly in the 1970s and now that I am back in the business again, I note they are still there.

A note re morphology, they seem to go from a very flaccid state where the dorsal surface is smooth as in Christina Bonsell's photos, to a contracted rough state exhibiting the papillae noted in Dave Behrens' photo. Another character I have noted is the relatively high profile and vertical sides to the foot at times when extended. Could this be an adaptation for cruising the mud below the surface for feeding and still keep the gills above the surface? Since there are apparently observers using ROVs, I thought I'd see if I could get an answer to this puzzle.
When did the term Tectibranch become so obsolete it disappeared completely?

Locality: Orange County coast, 20-30 fath plus/minus 10 fathoms, California, Pacific, 1970s to present 26 Mar 08, 16 ft otter trawl net. Length: Sea hare [Aplysia] sizes

markhowe@cox.net

Howe, M.W., 2008 (Mar 31) Re: Pleurobranchaea californica from Santa Barbara, California. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/21476

Hi Mark,

Interesting posting. Years ago I collected quite of few monster size specimens in the same area, via Rim Faye's - Pacific Biomarine. I was looking at the feeding habits of this giant vacuum cleaner. This is when we first learned that the species was cannibalistic, slurping up just about anything, including smaller individuals in its path.

Can't really comment on your question about the morphology of the photo, as I have never seen living specimens in their actual habitat. Your hypothesis seems right on certianly. Slow fish beware.

Concerning the old name Tectibranch, yes it bit the dust some time ago. Depending on who you follow, the group is now referred to as Notaspidea or the most recent, and correct - Pleurobranchomorpha.

Thanks for sharing this,
Dave Behrens

Behrens, D.W., 2008 (Mar 31). Comment on Re: Pleurobranchaea californica from Santa Barbara, California by Mark W. Howe. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/21476

Factsheet

Pleurobranchaea californica

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