Northwest Dive Club

I've never seen a black and orange clown nudi, is there a reason for this? I found this one today on Fox Island (East)

It could be something that it ate. I've seen some variations in other Nudibranch similar to this.

Scubie Doo wrote:It could be something that it ate.

Like what, licorice?

Maybe it's getting into the spirit of Halloween?

Echo wrote:I've never seen a black and orange clown nudi, is there a reason for this?

Hi Erika,

Smart ass answer #1 - You haven't seen one because you haven't been looking long enough or hard enough.
Smart ass answer #2 - Yes, there is a reason for the color variation.

More proper (and probably accurate) answer - The reason behind the color variation is most likely unknown because nudibranchs haven't really been studied that much. Here's an exchange from the Sea Slug Forum about another color variation in this species: http://www.seaslugforum.net/message/13733

Completely speculative answer #1 - The color variation could be related to diet in a number of ways. This species is known to eat bryozoans but it is apparently NOT known whether it eats one, a few, or many different bryozoan species. Dorid nudibranchs are often but not always extremely specialized in their diet. If this species has a more varied diet AND this individual has been eating a disproportionate amount of one particular prey then the individual's color could be affected.

Completely speculative answer #2 - Some bryozoan species are fairly short lived and seasonal. It's possible that your slug has been eating prey that is nearing the end of this stage of its life cycle. By extension, one can imagine that prey senescence might affect predator color.

Completely speculative answer #3 - Many nudibranchs are also fairly short lived and it is possible that the one you photographed is getting old. I can't tell, from the image, how large she is so speculation about how mature he is would be silly. This species is 'supposed' to reach somewhere between 6.5 and 7 inches in length so if your slug is nearing that size it could be getting old (but who knows?).

If you visit the Sea Slug Forum you might want to post your question there. If you do that it would be helpful to include size information and more complete location and depth information since the forum is based in Australia and the guy answering the questions is probably not familiar with Puget Sound dive sites.

Speculatively yours,
Alex

There were hundreds on the wall, mating. Laying eggs. This one was huge. And the only one of this color. I've been diving for 2 years as of this coming November, so your 'Smartass answer #1' could apply here, although I've seen thousands of these guys. Thanks for the info. Age and diet were my original speculations but thought there might be someone who knew more.

Been diving for 15 years (1200+ dives) around here and NEVER seen one that color. Very interesting!

It's the freaking coal trains!!
How's that for spreading fear and paranoia?