Nudibranchs are a group of soft-bodied, marine gastropod molluscs which shed their shells after their larval stage. They are noted for their often extraordinary colours and striking forms, and they have been given colourful nicknames to match, such as "clown", "marigold", "splendid", "dancer", "dragon", or "sea rabbit". Currently, about 3,000 valid species of nudibranchs are known.
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 actually 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.
Glaucus atlanticus is a species of small, blue sea slug, a pelagic aeolid nudibranch, a shell-less gastropod mollusk in the family Glaucidae.
Hermissenda crassicornis, also known as the opalescent nudibranch or thick-horned nudibranch, is a species of brightly coloured, sea slug or nudibranch, a marine gastropod mollusc in the family Facelinidae.
The Chromodorididae, or chromodorids, are a taxonomic family of colourful, sea slugs; dorid nudibranchs, marine gastropod mollusks in the superfamily Doridoidea. “Chromodorid nudibranchs are among the most gorgeously coloured of all animals.” The over 360 described species are primarily found in tropical and subtropical waters, as members of coral reef communities, specifically associated with their sponge prey. The chromodorids are the most speciose family of opisthobranchs. They range in size from <10mm to over 30 cm, although most species are approximately 15–30 mm in size.
A rhinophore is one of a pair of chemosensory club-shaped, rod-shaped or ear-like structures which are the most prominent part of the external head anatomy in sea slugs, marine gastropod opisthobranch mollusks such as the nudibranchs, sea hares (Aplysiomorpha), and sap-sucking sea slugs (Sacoglossa).
Bornellidae is a family of sea snails or sea slugs, marine gastropod mollusks in the superfamily Tritonioidea.
Bornella stellifer is a species of colorful sea slug, a nudibranch, a marine gastropod mollusk in the family Bornellidae.
Ceratosoma is a genus of sea slugs, dorid nudibranchs, shell-less marine gastropod mollusks in the family Chromodorididae.
Nembrotha cristata is a species of colourful sea slug, a polycerid nudibranch, a marine gastropod mollusk in the family Polyceridae. This species of sea slug is black with green markings; adults are around 50 mm in length, and they live on rock or coral reefs in the tropical Indo-West Pacific Ocean.
Bornella is a genus of sea slugs, specifically dendronotid nudibranchs in the family Bornellidae.
Phyllidia varicosa is a species of sea slug, a dorid nudibranch, a shell-less marine gastropod mollusc in the family Phyllidiidae.
Phyllodesmium is a genus of predatory sea slugs, aeolid nudibranchs, marine gastropod molluscs in the family Facelinidae.
Dendronotus is a genus of sea slugs, nudibranchs, marine gastropod molluscs in the superfamily Tritonioidea.
Tyrannodoris luteolineata is a species of sea slug, a polycerid nudibranch, a marine gastropod mollusc in the family Polyceridae.
A cnidosac is an anatomical feature that is found in the group of sea slugs known as aeolid nudibranchs, a clade of marine opisthobranch gastropod molluscs. A cnidosac contains cnidocytes, stinging cells that are also known as cnidoblasts or nematocysts. These stinging cells are not made by the nudibranch, but by the species that it feeds upon. However, once the nudibranch is armed with these stinging cells, they are used in its own defense.
Bornella irvingi is a species of sea slug, a nudibranch, a shell-less marine gastropod mollusc in the family Bornellidae.
Felimare alaini is a species of sea slug or dorid nudibranch, a marine gastropod mollusc in the family Chromodorididae.
Tritoniella is a genus of sea slugs, specifically dendronotid nudibranchs. It is a marine gastropod mollusc in the family Tritoniidae. A monotypic genus, the only species is Tritoniella belli. The genus and species were both described in 1907 by the British diplomat and malacologist Charles Eliot.
