Hermissenda explosion

[MaxBottomtime]

The past few weeks have brought an explosion of Hermissenda crassicornis to Marineland. Every rock at the point seems to have at least a dozen little guys crawling around, laying eggs and munching. We found a few eggs on a piece of kelp on Merry's first stage yesterday. After looking at it in her microscope I was amazed to see that each egg contained threee to four larvae fighting for space.

Click on next image to watch video

 

[JMdiver]

Hi Phil,

We were diving at Hawthrone Reef Sat. & they were all over there also.

John

 

[nannymouse]

"Hermissenda explosion"
Man! That sounds painful!!
You should see a doctor right away!
I think Dr. Bill would know what to do.

I am still working on going slowly so as to see small things like Hermissenda and, hopefully, tiny things like eggs.
The photos that I see make these nudies seem to be about 4-6" long, when some of them are less than 1".
Another recent revalation to me is that having 6 to 8 ft viz doesn't matter if you are slowly meandering along two feet above the rocks.

It's not how much you look at, it's how much you see! -Nannymouse

 

[drbill]

We've had a few pulses like that here on Catalina as well. Usually they occur in deeper water, but at Ship Rock (and possibly some of the West End sites) they seem to be shallower. Good food sources help so cold water, rich in nutrients to feed the plankton and therefore the bryozoa and hydroids seems to help.

 

[TSandM]

Thanks for the video! Great to learn something new about these animals.

It's funny how nudibranchs seem to go in waves like that . . . We had two years of hooded nudibranchs EVERYWHERE, and now they've dropped back to normal levels.

 

[divinman]

Gorgeous shot Phil. They are all over down here in the kelp off Pt Loma as well.

 

[drbill]

It's funny how nudibranchs seem to go in waves like that . . . We had two years of hooded nudibranchs EVERYWHERE, and now they've dropped back to normal levels.

I remember back in the early 70's we had a pulse of these (Melibe leonina). I was out with my students sampling drifting kelp rafts off the east end of the island. We pulled up one raft that seemed to have thousands of them... mostly copulating. Here are a few of them that I brought back to the tanks in the lab:

 

[robint]

Wow! great pics everyone! I can't wait to get back out there again in August. Great Escape, here we come!

robin

 

[MaxBottomtime]

"Hermissenda explosion"
I am still working on going slowly so as to see small things like Hermissenda and, hopefully, tiny things like eggs.
The photos that I see make these nudies seem to be about 4-6" long, when some of them are less than 1".
Another recent revalation to me is that having 6 to 8 ft viz doesn't matter if you are slowly meandering along two feet above the rocks.

It's not how much you look at, it's how much you see! -Nannymouse

Many of the Dendronotus iris at Marineland are 6-8" long. I also found a six inch Anisdoris nobilis yesterday. Sometimes I will spend several minutes staring at the same rock. When I download my pictures I always find tiny animals I didn't see under water. The worst part is looking at water samples under a microscope. There are more animals in a dish of water than some zoos. And this is the water we get in our eyes and mouth.

 

[drbill]

I think the D. iris I saw here off Catalina was about 4" Phil. Your pic is definitely great. I do see Peltodoris nobilis in the 6" range fairly regularly, but only at depth (usually 100-160').