This is a nudibranch. Nudibranchs are hermaphroditic gastropods, although they can only rarely impregnate themselves. One set of its feelers, the flanged rhinopores, smells the ocean, while the other cephalic (or head) tentacles and allow the animal to smell, taste and touch.
The colorful spiky bits are intestinal protuberances, containing the stinging nematocysts of their foods. So, nudibranch can eat anemones, and harvest and utilize the anemone's stinging power. If you are going to have external intestinal organs, they may as well be useful.
Useful and pretty, right?
We spotted two nudis when we were out tidepooling on Tuesday. The first one was a little over an inch in length. The lower one, which was clinging onto a snail's shell was about half that size. Our tidepool guide, John found some even smaller, but had set all his nudis free just before we arrived.
We did not disturb the hitch hiker nudibranch, but we did scoop the large one into a plastic bowl, and slip a piece of seaweed under it. Yeah, I'll admit it. I'm a nudibranch prop stylist. No nudibranchs were harmed in the making of this picture.
This is a solitary anemone. Anemones get their green coloration from zooxanthellae, an algae with whom they form a symbiotic relationship. The algae lives inside the anemone, which uses the algae's photosynthetic products as a source of carbohydrates. The algae, in turn, consume the waste products of the anemone.
This lemon meringue of an anemone is apparently deficient in zooxanthella. These are humongous anemones, maybe six inches across.
These, on the other hand, were teeny-tiny. Neither of these anemones were ay larger than a dime. They had such astonishing coloration that, even at that size, they were hard to miss.
This one, which looks like blown glass, lived right at the water's edge. Life must be very precarious, indeed, for a creature of this kind.