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.
Aplysiidae is the only family in the superfamily Aplysioidea, within the clade Anaspidea. These animals are commonly called sea hares because, unlike most sea slugs, they are often quite large, and when they are underwater, their rounded body shape and the long rhinophores on their heads mean that their overall shape resembles that of a sitting rabbit or hare. Sea hares are however sea snails with shells reduced to a small plate hidden between the parapodia, and some species are extremely large. The Californian black sea hare, Aplysia vaccaria is arguably the largest living gastropod species, and is certainly the largest living heterobranch gastropod.
Bulla is a genus of medium to large hermaphrodite sea snails, shelled marine opisthobranch gastropod molluscs. These herbivorous snails are in the suborder Cephalaspidea, headshield slugs, and the order Opisthobranchia.
Octopus is the largest genus of octopuses, comprising more than 100 species. These species are widespread throughout the world's oceans. Many species formerly placed in the genus Octopus are now assigned to other genera within the family. The octopus has 8 arms, averaging 20 cm long for an adult. Octopodidae.
The Pleurobranchidae are a taxonomic family of sea slugs, marine gastropod molluscs in the clade Pleurobranchomorpha.
Chromodoris is a genus of very colourful sea slugs or dorid nudibranchs, marine gastropod molluscs, and the type genus of in the family Chromodorididae. Within the genus Chromodoris, there are currently 101 classified species. Species within Chromodoris are commonly found in tropical and subtropical waters, living as members of reef communities and preying primarily on sponges. A molecular phylogeny of the family Chromodorididae resulted in this genus being restricted to a smaller number of species than formerly, most of which have longitudinal black lines on the mantle. Many former members of Chromodoris were transferred to Goniobranchus
Glossodoris is a genus of sea slugs, dorid nudibranchs, shell-less marine gastropod mollusks in the family Chromodorididae.
Doris is a genus of sea slugs, specifically dorid nudibranchs. These animals are marine gastropod molluscs in the family Dorididae.
Kikutaro Baba was a Japanese malacologist. He was the leading researcher on sea slugs and bubble snails, opisthobranch gastropod mollusks in Japan.
William B. Rudman, usually known as 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.
Goniodoris is a genus of sea slugs, specifically dorid nudibranchs, marine gastropod molluscs in the family Goniodorididae.
Felimida is a genus of sea slugs, dorid nudibranchs, shell-less marine gastropod mollusks in the family Chromodorididae.
Felimare is a genus of sea slugs, dorid nudibranchs, shell-less marine gastropod molluscs in the subfamily Miamirinae of the family Chromodorididae.
Thomas Everett Thompson PhD DSc FZS was a British malacologist and embryologist, known for his extensive studies on opisthobranch molluscs.
