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:
“At the same time that we are earnest to explore and learn all things, we require that all things be mysterious and unexplorable, that land and sea be infinitely wild, unsurveyed and unfathomed by us because unfathomable.”
—Henry David Thoreau (1817–1862)
“Adrift dissolving, bound for death;
Though lumpish thou, a lumbering one—
A lumbering lubbard loitering slow,
Impingers rue thee and go down,
Sounding thy precipice below,
Nor stir the slimy slug that sprawls
Along thy dead indifference of walls.”
—Herman Melville (1819–1891)