This San Diego Dorid was crawling through a maze of kelp at Tajiguas. The rhinophores look extended, curious and eager to see what's next down the path; and with all the spiraled ridges they should be able to tell a lot about it!
The polyps of a golden gorgonian strain out of their homes, extending their tentacles to grab passing food particles. This scene is about the size of a fingernail; the entire coral fan is about a foot high. The sea fan was at Tajiguas, where conditions have been reasonable lately and there are lots of gorgonians just off the beach.
This Hermissenda crasicornis was crawling across a blade of kelp at Tajiguas. The common name is "Opalescent nudibranch" which is nice too, but somehow the Latin name seems more descriptive in this case.
Christine Donahue, and collaborators Clint Nelson, Dan Reed and Shannon Harrer, have come up with a great field guide to locally common plants and animals. To me, the best aspects of this guide are the algae and inverts. It resolved a lot of the doubts and questions I have about those plants and animals that you see everywhere on the bottom, and seem to take a few different forms that may be related. Like, what are those big single-bladed algae that look like laminaria, but are completely smooth and have a central rib? (They are young sea palms). It distinguishes between coastal and island environments: which are pof course retty different. And, it's free for the downloading: http://sbcdata.lternet.edu/external/Documents/Publications/FieldGuide.pdf
This nudibranch looks like it's glowing redly from within as it erupts from a blade of red algae. Actually the strobe is shining through the kelp, illuminating an opalescent nudibranch (Hermissenda crassicornis). When the surge passes and the kelp blade turns, the same nudibranch an instant later still looks like it's glowing from within -- but with white light rather than red, from the unfiltered strobe. So it's really that color, right? Well, when not illuminated by the strobe it looks pretty bland, to eyes or cameras. No doubt it looks pretty different to the underwater creatures, who have eyes that see different colors -- when they have eyes at all.
These look like big, orange versions of the yellow nudibranchs known as "sea lemons". We call them sea oranges. I am not good at nudibranch identification but I will guess that it is one of the Dendrodorids. We found it on the urchin barrens, on the west side of Refugio Beach. It was about the size of a golf ball.
It's interesting how everything under water gets named after something above water. We have sea lemons, sea apples, seaweed, sea urchins, and now sea oranges and sea hedgehogs.
Herman Melville wrote in Moby Dick, in the wonderful chapter "Brit":
For though some old naturalists have maintained that all creatures of
the land are of their kind in the sea; and though taking a broad
general view of the thing, this may very well be; yet coming to
specialties, where, for example, does the ocean furnish any fish that
in disposition answers to the sagacious kindness of the dog? The accursed shark alone can in any generic respect be said to bear comparative analogy to him.
The labrador retriever of the sea is definitely the sheephead (which have nothing to do with sheep's heads, so far as I can tell). Sharks seem more like cats: maybe bobcats or cougars. Hermann should have learned to scuba dive.
Sea hares are giant, slow-moving, sea-dwelling slugs. They like to inhale lots of seawater to puff themselves up. To deter predators, they release clouds of foul black ink when they feel threatened. They mate in big disorganized clusters and then lay strings of eggs like mad: at times their eggs are all over the place underwater. This one was about 6 inches long, although I've seen much larger. Actually, they sound a lot like the underwater equivalents of rabbits.
Sea apples are short, round sea cucumbers. The frilly stuff is the tongue -- err, feeding apparatus, which they extrude to gather food and then periodically swallow so as to clean off the edibles. I usually think of sea apples as not-particularly-exciting wallpaper on the bottom. They seem to have more interesting structure and color, when seen from close up.
A biologist tells me that this is an isopod, of the genus Idotea. You can see it crawling down the base of the sea apple above.