Two Nudibranchs I'd like help to ID...

[Huskychemist]

Coachrenz, Jackie and I did a great dive at Redondo last night.

On the way back, under the pilings, I saw two nudibranchs that I have yet to positively ID, and I could use some help...

The first one (well, there are actually two...) was very small...2 cm at the most...and has some markings that make me think it might be a color variant of Onchodoris bilamelata. But I've never seen this color before on that particular species.




The second nudibranch is a pair of them that are...um...quite close. My guess on the genus is Acanthodoris. There is a species, Acanthodoris brunnea that has similar color, but the species I photographed seems to have much narrower papilla than any of the pictures I've seen of Acanthodoris brunnea. Any thoughts? (And sorry that the second picture is a bit big. I wanted to leave it "original" size to show the detail.





Thanks!

And both pictures were cropped, but no other "photoshopping."

[John Rawlings]

The first one (well, there are actually two...) was very small...2 cm at the most...and has some markings that make me think it might be a color variant of Onchodoris bilamelata. But I've never seen this color before on that particular species.

Hmmmm.....it's difficult to tell, and I'm FAR from certain, but I wonder if the FIRST one might be Acanthodoris bunnea, rather than the second one as you surmise. It is aka the "Brown Horned Dorid".

This species is named for its rich dark brown color. It feeds on bryozoans and has a huge range from Vancouver Island, BC, in the North to Santa Monica, California, in the South. Your photo looks similar, although a deeper brown, than the lower photo shown in Eastern Pacific Nudibranchs.

The second nudibranch is a pair of them that are...um...quite close. My guess on the genus is Acanthodoris. There is a species, Acanthodoris brunnea that has similar color, but the species I photographed seems to have much narrower papilla than any of the pictures I've seen of Acanthodoris brunnea. Any thoughts? (And sorry that the second picture is a bit big. I wanted to leave it "original" size to show the detail.

There are several among the Dorids that I think are appear to be close, but do not seem to match exactly. Nudibranchs can be frustrating that way!

Try e-mailing the images to David Behrens at Sea Challengers in Gig Harbor to see if he has any ideas. Dave REALLY knows his Nudis! (He's the author of the book mentioned above). I'd give you his personal e-mail, but I don't know if he'd want that broadcast on the web! Here's the business e-mail, and I know that he responds to it:

info@seachallengers.com

- John

[Huskychemist]

I sent an e-mail to Dave, as you suggested. I'll let you know when I hear anything back from him.

Thanks!

And your comment about the first one made me go back to his book and look again. His description of A. brunnea mentions "yellow tipped branchial plume..." Hmmmm....

Isn't "branching" fun!

Lowell

[John Rawlings]

I'm going to be very interested in hearing what he says! Nudibranchs can be SO varied.....it boggles the mind!

- John

[Huskychemist]

For the first nudibranch above (brown, with bright yellow tips to the rhinophores and branchial plumes):

Palio dubia

Beheren's description in his book Eastern Pacific Nudibranchs, coauthored with Alicia Hermosillo, is pretty good. It mentiones the yellow coloration, brown "background" etc.


And the second nudibranch is:

Acanthodoris pilosa

(Boasting here that I had the genus correct!) This seems close to A. brunnea, but brunnea has conical papillae, whereas this species has longer, narrower papillae.

Fun stuff! Thanks for the suggestion John.

Two more species to add to my list! Woohoo!

Lowell

[John Rawlings]

Wow! I never would have come up with P. dubia in a million years! No wonder it's called the "Dubious Dorid"! HA!

A. pilosa, on the other hand, WAS on my "short list" for the second one! WHEW!

We need people like Dave around to help the rest of us figure things out!

- John

[Jan K]

Dubious Dorid is not that common, great find! I had only one encounter at Langley last year, what was interesting, I collected two specimen for Dave, when I took them home, they turned brown, more like the ones in your photo..

[John Rawlings]

OK, Jan....the cats-out-of-the-bag now! We now have PROOF that you can post your photos here!

I hope that you will regularly share more of your beautiful work with us here on NWDC. Why should the Northwest Diver site have all the fun?!!! HA!

- John