Sea slug is a common name used for several different groups of saltwater snails that either lack a shell or have only an internal shell. It is a paraphyletic name used for various lineages of marine gastropod mollusks that are either not conchiferous (shell-bearing) or appear not to be.
The phrase "sea slug" is often applied to nudibranchs (many members of which are colorful and are a noticeable part of the underwater fauna), sea hares, the sacoglossans, various families of bubble snails (Cephalaspidea), the sorbeoconch family Pterotracheoidea, the pulmonate (air-breathing) sea slug family Onchidiidae, and others.
Read more about Sea Slug: Reproduction
Famous quotes containing the words sea and/or slug:
“For half a mile from the shore it was one mass of white breakers, which, with the wind, made such a din that we could hardly hear ourselves speak.... This was the stormiest sea that we witnessed,—more tumultuous, my companion affirmed, than the rapids of Niagara, and, of course, on a far greater scale. It was the ocean in a gale, a clear, cold day, with only one sail in sight, which labored much, as if it were anxiously seeking a harbor.... It was the roaring sea, thalassa exeessa.”
—Henry David Thoreau (1817–1862)
“Before me you are a slug in the sun. You are privy to a great becoming and you recognize nothing. You are an ant in the afterbirth. It is in your nature to do one thing correctly: tremble.”
—Michael Mann, U.S. screenwriter. Frances Dollarhyde, aka “The Tooth Fairy” (Tom Noonan)