Nudibranchs belong to the order Nudibranchia, a group of soft-bodied marine gastropod molluscs that 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", and "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 gastropods, i.e. they are sea snails that, over evolutionary time, have either entirely lost their shells or have seemingly lost their shells due to having a significantly reduced or internal shell. The name "sea slug" is often applied to nudibranchs and a paraphyletic set of other marine gastropods without apparent shells.
The chondrophores or porpitids are a small group of hydrozoans in the family Porpitidae. Though it derives from an outdated name for this lineage, some still find the term 'chondrophore' useful as a synonym to 'porpitid' in discussions of the two genera contained therein, Porpita and Velella.
Velella is a monospecific genus of hydrozoa in the Porpitidae family. Its only known species is Velella velella, a cosmopolitan free-floating hydrozoan that lives on the surface of the open ocean. It is commonly known by the names sea raft, by-the-wind sailor, purple sail, little sail, or simply Velella.
Glaucus atlanticus is a species of small, blue sea slug, a pelagic (open-ocean) aeolid nudibranch, a shell-less gastropod mollusk in the family Glaucidae.
Dendronotoidea is a taxonomic superfamily of small colorful sea slugs or nudibranchs, aeolid nudibranchs.
Fiona pinnata, common name Fiona, is a species of small pelagic nudibranch, a marine gastropod mollusk in the superfamily Fionoidea. This nudibranch species lives worldwide on floating objects on seas, and feeds mainly on barnacles, specifically goose barnacles in the genus Lepas.
Janthina janthina is a species of holoplanktonic sea snail, a marine gastropod mollusk in the family Epitoniidae. Its common names include violet sea-snail, common violet snail, large violet snail and purple storm snail.
Porpita porpita, or the blue button, is a marine organism consisting of a colony of hydroids found in the warmer, tropical and sub-tropical waters of the Pacific, Atlantic, and Indian oceans, as well as the Mediterranean Sea and eastern Arabian Sea. It was first identified by Carl Linnaeus in 1758, under the basionym Medusa porpita. In addition, it is one of the two genera under the suborder Chondrophora, which is a group of cnidarians that also includes Velella. The chondrophores are similar to the better-known siphonophores, which includes the Portuguese man o' war, or Physalia physalis. Although it is superficially similar to a jellyfish, each apparent individual is actually a colony of hydrozoan polyps. The taxonomic class, Hydrozoa, falls under the phylum Cnidaria, which includes anemones, corals, and jellyfish, which explains their similar appearances.
Phyllodesmium is a genus of predatory sea slugs, aeolid nudibranchs, marine gastropod molluscs in the family Facelinidae.
William B. "Bill" Rudman is a malacologist from New Zealand and Australia. In particular he studies sea slugs, opisthobranch gastropod molluscs, and has named many species of nudibranchs.
Glaucus is a genus of small blue pelagic sea slugs. They are aeolid nudibranchs, ranging in size from 20 to 40 mm. They feed on colonial cnidarians such as Portuguese man o' wars, blue buttons, and purple sails. They can produce painful and potentially dangerous stings when handled, as they store the venomous nematocysts of their prey. Glaucus is the only genus in the family Glaucidae. It includes five species.
Pteraeolidia ianthina is a sea slug, an aeolid nudibranch in the family Facelinidae. It is known as a blue dragon, a name it shares with Glaucus atlanticus and Glaucus marginatus.
Felimare cantabrica is a species of colourful sea slug or dorid nudibranch, a marine gastropod mollusc in the family Chromodorididae.
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.
Tenellia behrensi is a species of sea slug, an aeolid nudibranch, a marine gastropod mollusc in the family Fionidae.
Trinchesia macquariensis is a species of sea slug, an aeolid nudibranch, a marine gastropod mollusc in the family Trinchesiidae.
Cerberilla incola is a species of sea slug, an aeolid nudibranch, a marine heterobranch mollusc in the family Aeolidiidae.
Thomas Everett Thompson PhD DSc FZS was a British malacologist and embryologist, known for his extensive studies on opisthobranch molluscs.
Herviella cloaca is a species of sea slug, an aeolid nudibranch, a marine gastropod mollusc in the family Facelinidae.
