Sea slug is a common name for some marine invertebrates with varying levels of resemblance to terrestrial slugs. Most creatures known as sea slugs are gastropods, i.e. they are sea snails that over evolutionary time have either completely lost their shells, or have seemingly lost their shells due to having a greatly reduced or internal shell. The name "sea slug" is most often applied to nudibranchs, as well as to a paraphyletic set of other marine gastropods without obvious shells.
Opisthobranchs is a now informal name for a large and diverse group of specialized complex gastropods which used to be united in the subclass Opisthobranchia. That taxon is no longer considered to represent a monophyletic grouping.
Navanax inermis, common name the California aglaja, is a large species of predatory sea slug, a marine opisthobranch gastropod mollusk in the family Aglajidae. Navanax is not a nudibranch, even though it somewhat resembles one; it belongs to a more ancient lineage of opisthobranchs called the cephalaspideans or head shield slugs and snails.
Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the absence of a visible shell.
Notaspidea, also known as the sidegill slugs, is an artificial grouping of sea slugs which is now split into two unrelated groups, the Umbraculida and the Pleurobranchomorpha.
Umbraculum umbraculum, common name the umbrella slug, is a species of large sea snail or limpet, a marine gastropod mollusc in the family Umbraculidae. It is found in tropical to warm temperate parts of the Indo-Pacific and Atlantic Oceans, where it feeds on sponges.
Acanthodoris lutea, the orange-peel doris, is a species of nudibranch or sea slug, a shell-less marine opisthobranch gastropod mollusk in the family Onchidorididae.
Peltodoris nobilis, commonly called the sea lemon, false sea lemon, or the noble dorid, is a species of colorful sea slug, a dorid nudibranch, a shell-less marine gastropod mollusk in the family Discodorididae.
Tylodinidae is a family of sea snails or false limpets, marine opisthobranch gastropod mollusks in the superfamily Umbraculoidea.
Phyllidia babai is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusk in the family Phyllidiidae.
Tylodina is a genus of medium-sized sea snails or false limpets in the family Tylodinidae.
Mexichromis tura is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusk in the family Chromodorididae.
Aplysina insularis, commonly known as the yellow-green candle sponge or yellow candle sponge, is a species of sea sponge found on reefs in the Caribbean Sea and the Gulf of Mexico.
Chelidonura electra is a species of sea slug, a "headshield slug", a marine opisthobranch gastropod mollusk in the family Aglajidae. The species name comes from the daughter of Agamemnon, Electra, and the Greek goddess of the same name, meaning "shining", with reference to the brilliance of this slug.
Aplysina is a genus of sea sponges in the order Verongiida. It was first authenticated and described by Giovanni Domenico Nardo in 1834.
Tylodina fungina, commonly known as the yellow umbrella slug or the mushroom sidegill, is a species of sea snail or false limpet, a marine opisthobranch gastropod mollusk in the family Tylodinidae.
Aplysina fistularis, also known as the yellow tube sponge, is a species of sea sponge in the order Verongiida. Aplysina fistularis is a golden or orange-brown color with a conulose surface. The animal is abundant in the Caribbean, where it is commonly found in reefs of open water areas. This sponge was first described by the Prussian zoologist Peter Simon Pallas in 1766.
Aplysina aerophoba is a species of sponge in the family Aplysinidae. It is a yellow, tube-forming or encrusting sponge and is native to the eastern Atlantic Ocean and the Mediterranean Sea; the type locality is the Adriatic Sea.
