Dendronotus iris in Catalina waters

[drbill]

I've commented a number of times on various SoCal boards that I've never seen a Dendronotus iris nudibranch in Catalina waters. That is, until today. We were in the Twin Rocks-Goat Harbor area and I dropped down to about 120 and started working my way up. I saw a Pachycerianthus anemone tube that appeared to have a hairy reddish growth on the side.

As I rounded the tube I saw that it was a D. iris crawling up to the opening of the tube. WOW! I've seen lots of great pix of them from mainland waters, and seen a few myself without a camera. Over nearly 40 years and several thousand dives in our waters, this is the first one I remember seeing. I'll post stills later after I've captured today's footage.

My reason for posting is to ask all the nudibranch lovers who dive Catalina waters if THEY have seen them here? I'm really curious since until today I've had no concrete evidence that they enter our waters.

 

[MaxBottomtime]

Congratulations!! I only found a couple at Marineland today, so maybe they are headed back to deeper waters. I've never seen one at Catalina before.

 

[drbill]

Nice shot, Phil! Will be interesting to see if others have.

 

[robint]

Wow! I would love to see one of those guys but I really don't want to have to go that deep! Has anyone ever seen them shallower?

 

[dannobee]

Wow! I would love to see one of those guys but I really don't want to have to go that deep! Has anyone ever seen them shallower?

There are a LOT of them in Monterey around the Breakwater and Metridium fields. Depth around 40-50ish.

These do get fairly large-the bigger ones get about a foot long. 6-8 inches is very common. One trick to get the cool pics is to pick them up and let them fall through the water column.

 

[drbill]

Here is a collage of images that I will be using for an upcoming newspaper column on the sighting. Note in the second image on top that I used Dannobee's suggestion before I even read it!

According to Behrens and Hermosillo, it is a widely distributed species found from Unalaska to Cabo San Lucas. My guess is that it exhibits some submergence as one goes further south into warmer water so its presence in shallow water is much more likely in the northern part of its range.

 

[TSandM]

Interesting theory . . . They are not uncommon here, and we find them quite shallow, so you may be right.

 

[MissyP]

They've been around the rim of the canyon & on the canyon walls at La Jolla Shores for years~ 45-60ft or so..

Wow! I would love to see one of those guys but I really don't want to have to go that deep! Has anyone ever seen them shallower?

 

[drbill]

Yeah, but despite the fact that you are further south, Missy... it's COLDER there. Brrr! Now you showed me the Melibe leonina there, but not the D. iris... would have been nice to film them there where I'd actually have some decent bottom time!

 

[drbill]

Submergence is a well known phenomenon when a northern species exists in waters further south. Just the difference of ~100 miles between the colder northern Channel Islands and warmer Catalina (especially from Long Point to the East End) is enough to drive common subjects from the north much deeper here.

Although nudies are supposed to have bad taste (that is they taste poor, I think they are quite beautiful) I also believe that the relative lack of sheephead and other predatory fish in the northern islands and on the SoCal mainland is another potential factor. I have seen sheephead, kelp bass, garibaldi and other predatory fish take them in their mouths and spit them out. However, when faced with hunger, I'm known to eat my own cooking and they may decide a nudibranch is better than nothing.