Originally posted by Racer X 69 Some folks here call them sea slugs (although there may be some other creature in the Sound that answers that description more aptly).
Oh yes. Sea slugs are gastropods like land slugs, and are really beautiful, fragile-looking creatures sometimes with wonderful colors. They look as if defenseless to predators, but they feed on corals, anemones and other Coelenterates (pardon use of the old term for these creatures) and transfer the stinging cells called nematocysts to the surface of their skin. Biting one is like biting the stinging tentacles of a jellyfish (= another type of coelenterate). If you've never seen a sea slug, it's worth GOOGLING images. Way back I looked at them at Moss Beach, CA, during a summer course in invertebrate zoology.
To envision a sea cucumber:
1) start with a starfish;
2) Imagine the central small area where the arms connect extended as a chunky, cylindrical column;
3) reduce the lengths of the five arms and make them feathery, instead of a single tapering arm;
4) remove essentially all of the hard carbonate plates so the entire column and feathery arms are soft and floppy rather than rigid and hard like a starfish;
5) now you have more-or-less converted a starfish into a sea cucumber.