Nudibranch - Channel Islands, California

[eponym]

I've looked at some SoCal slug ID sites but haven't found the one I saw, so here goes. Don't have a photo of it.

Spotted a nudi (I think) on a dive last week. I was in Southern California, off West Anacapa Island (in the Channel Islands). The skipper called the site "Three Fingers Cave."

The dive started at midday. The critter was motionless on a vertical piece of bare rock, a couple of inches above the sand bottom, at about 48 FSW. Water temp around 63.

This critter is about two inches long and three-quarter inches across, or maybe smaller.
The body is black with very fine white dots, fine enough to give an impression of velvet.
It sports two bright stripes running from head (wide apart) to tail (closer together).
Each stripe is composed of a red line and a blue line.
The stripes are startlingly bright and very narrow, like very fine piping.

Any guesses or pointers?

 

[Searcaigh]

Any rhinophores or obvious gills?

 

[eponym]

I could see two rhinophores, same coloring (black).

 

[drbill]

Are you sure it wasn't a flatworm?

 

[eponym]

Not sure at all. My vision's not what it used to be.
And my field ID skills aren't much better.

Good suggestion. Here's an image of a flatworm that's similar in coloration, except it lacks the reb & blue piping. And I didn't notice a white edge.

 

[MaxBottomtime]

It sounds more like Navanax inermis.

 

[merxlin]

It sounds more like Navanax inermis.

That's what I was thinking.

 

[drbill]

Or possibly Navanax polyalphos given the description of fine white dots

 

[eponym]

Yes, N. inermis looks like it. Nice photo!
Thanks, Max, Dr. Bill, for the help.
I think it's finally time for me to tote a camera on my dives . . .

Bryan

 

[TSandM]

That was the primary reason for me to pick up a camera -- I wanted to be able to look stuff up in my books!