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.
Heterobranchia, the heterobranchs, is a taxonomic clade of snails and slugs, which includes marine, aquatic and terrestrial gastropod mollusks.
The order Cephalaspidea, also known as the headshield slugs and bubble snails, is a major taxon of sea slugs and bubble snails, marine gastropod mollusks within the larger clade Euopisthobranchia. Bubble shells is another common name for these families of marine gastropods, some of which have thin bubble-like shells. This clade contains more than 600 species.
Pulmonata or pulmonates is an informal group of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group includes many land and freshwater families, and several marine families.
Euthyneura is a taxonomic infraclass of snails and slugs, which includes species exclusively from marine, aquatic and terrestrial gastropod mollusks in the clade Heterobranchia.
Lower Heterobranchia, also known as the Allogastropoda, is a group of rather specialized, highly evolved sea slugs and sea snails, within the subclass Heterobranchia.
Acochlidiacea, common name acochlidians, are a taxonomic clade of very unusual sea snails and sea and freshwater slugs, aquatic gastropod mollusks within the large clade Heterobranchia. Acochlidia is a variant spelling.
Umbraculoidea is a superfamily of unusual false limpets with a thin soft patelliform shell, marine gastropod molluscs in the clade Umbraculida, within the clade Euopisthobranchia.
Runcinoidea is a taxonomic superfamily or a clade Runcinaecea of sea slugs, marine gastropod mollusks in the order Runcinida
This overview lists proposed changes in the taxonomy of gastropods at the family level and above since 2005, when the taxonomy of the Gastropoda by Bouchet & Rocroi (2005) was published. In other words, these are recent updates in the way various groups of snails and slugs are classified.
Acochlidium fijiiensis is a species of freshwater gastropod, an aquatic gastropod mollusc within the family Acochlidiidae. Acochlidium fijiiensis has no shell.
Pseudunela is a genus of minute sea slugs, acochlidians, shell-less marine or temporary brackish or brackish gastropod mollusks in the clade Acochlidiacea.
Aiteng ater is a species of sea slug, a marine gastropod mollusc in the family Aitengidae. The specific name ater is from the Latin language and means black, in reference to the appearance of the slug on the mud.
Aiteng is a genus comprising three species of sea slug, A. ater and A. mysticus being found in intertidal zones while A. marefugitus is fully terrestrial. Aiteng is the only genus in the family Aitengidae. The generic name Aiteng is derived from the name of a black puppet Ai Theng, which is one of the shadow play puppets in southern Thailand.
Panpulmonata is a taxonomic clade of snails and slugs in the clade Heterobranchia within the clade Euthyneura.
Pontohedyle milaschewitchii is a species of sea slug, an acochlidian, a shell-less marine gastropod mollusk in the family Parhedylidae.
Pontohedyle is a genus of sea slugs, acochlidians, shell-less marine gastropod mollusks in the family Parhedylidae. Sea slugs in this genus are highly simplified and uniform.
Pseudunela viatoris is a species of sea slug, an acochlidian, a shell-less marine gastropod mollusk in the family Pseudunelidae.
Pseudunela marteli is a species of sea slug, an acochlidian, a shell-less marine gastropod mollusk in the family Pseudunelidae.
Aiteng marefugitus is a species of fully terrestrial sea slug found only on the Ulong Island of Palau. The species name is derived from Latin, meaning "fled from the sea".
