Dendronotus iris in Catalina waters

[MissyP]

Cold is just a state of mind Come back down & we'll go find some d. irises :-D
Leopards are going to be around soon as well....

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!

 

[MaxBottomtime]

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?

Most of the ones laying eggs at Marineland are in forty feet.

 

[drbill]

Hey, Phil... what's the temp like at that depth off Marineland? I seem to find most nudies (other than Hermissendas, Flabellinas and Mexichromis) in temps of about 50-55 F. The temp at 112 ft when I found the D. iris was a toasty 52 F. You've seen my "holy" wetsuit so you can marvel at the fact the footage did not exhibit any camera shake from the cold!

 

[MaxBottomtime]

My computer has been giving me temps a couple of degrees colder than Merry's. Mine read 45.7F on Sunday. Merry's was 50F. There is a deep-water dropoff south of the point that keeps Marineland consistantly colder than other sites. With the shallow Huntington Flats offshore in Orange County, Laguna Beach temps can be as much as ten degrees warmer than Marineland. The good news is that the cold water upwelling brings enough nutrients to feed an incredible diversity of life at the point..

 

[robint]

very interesting! I hadn't even thought that the water temp had to do with finding nudies. Last couple of years we dove up around Anacapa/Santa Cruz (aprox. 12 dives) and saw many nudies, all different species (water temps ranged 60-65). It was really amazing! Once we learned what to look for we started finding them everywhere. It was sooooo coooool.

Then last summer we did 2 days at Catalina/Santa Barbara and only saw a few spanish shawls, no other nudies (water temps 66-70). We thought it might have something to do with water temp... :11: but didn't realize how much.

I would love to see nudies again this trip (in August) but we will be in southern islands again. I hope to finally see my first horn shark, too. Three trips to Calif and I still haven't found one!!!

 

[drbill]

Wow... I'm glad that I haven't had the "pleasure" of diving Marineland then. I think ice would form inside my wetsuit.

Yes, temperature plays a role due to the fact that water above 68 F (20 C) is pretty nutrient poor whereas below that inflection point, nutrients increase with decreasing temperature. More nutrients (assuming sufficient light) generally means more phytoplankton which means more for nudie food (hydroids, bryozoans, etc.) to munch on... hence, more nudies!

 

[Empty V]

...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.

Hey Dr. B thanks for all the great info. When I first started doing the aquarium thing I was told that nudies are off limits mostly because they're extremely hard to keep alive and when they die they secrete a poison much like anemones. This can cause your tank to crash and kill everything not immune to it (most commonly eels and clownfish survive). Do you know if this is correct?

Billy

 

[drbill]

Hey Dr. B thanks for all the great info. When I first started doing the aquarium thing I was told that nudies are off limits mostly because they're extremely hard to keep alive and when they die they secrete a poison much like anemones. This can cause your tank to crash and kill everything not immune to it (most commonly eels and clownfish survive). Do you know if this is correct?

Billy

Billy,

I can only answer from my personal experience. When I operated a lab in conjunction with my high school marine biology program, we had 12 tanks of 50 gal capacity but no running sea water. As long as we changed the water in the tanks with reasonable frequency (every 1-2 weeks), the nudies seemed to have no problem. Of course I made sure they had some munchies in the tank.

The species I had trouble with, as expected, were the octopuses and the mucous secreters.