Sea Butterflies
Naked Sea Butterflies Clione limacina resemble angels. They have a spindle-shaped body up to 1 inch long that is bluish and transparent, with pink to red-yellow areas. The shell is absent. The head is well developed and clearly evident because of an indentation on the upper part of the body. The body has robust flaps ( mantle lobes ) that are used for propulsion. Although it looks like a jellyfish, the Naked Sea Butterfly is a gastropod mollusk, related to snails and sea slugs, and does not sting.
The Atlantic Corolla is a swimming snail with a soft, transparent gelatinous body. It looks like a jellyfish but it is not. A truly planktonic opisthobranch that, being negatively buoyant, must swim with its large wing-like foot.
The many creatures on this page are lumped together for the one trait they all have in common - they are all "jelly-like" - soft, gelatinous, and more-or-less transparent. Other than that, they are for the most part completely unrelated. True Jellyfishes, Hydromedusae, and Siphonophores are in the phylum Cnidaria, related to bottom-dwelling Hydroids, Sea Anemones, and corals. Comb Jellies are in the phylum Ctenophora, and are completely unrelated to jellyfishes, as are Sea Butterflies and Corollas, which are mollusks. Salps are free-swimming tunicates, more closely related to us than to any of these other creatures.
More: Jellyfishes ...
