What is Nudibranch?
{{Taxobox | name = Nudibranch | image = Berghia coerulescens (Laurillard, 1830) .jpg | image_caption = ''Berghia coerulescens'' | regnum = [[Animal]]ia | phylum = [[Mollusca]] | classis = [[Gastropoda]] }} [[File:Kubaryana eating clavelina.jpg|thumb|Nudibranchs (''Nembrotha kubaryana'') eating ''clavelina'' [[tunicate]] colonies. They also take the stinging cells of jellyfish when they eat them.]] [[File:Phyllidiopsis papilligera (Black-spotted Nudibranch - North Haiti).jpg|thumb|Black-spotted Nudibranch from North of [[Haiti]]]] [[File:Chromodoris willani Lembeh.JPG|thumb|''Chromodoris willani''<br>Lembeh Straits, [[Indonesia]]]] [[File:Cerberilla ambonensis nudibranch.jpg|thumb|''Cerberilla ambonensis'', a burrowing nudibranch from East Timor]] '''Nudibranchs''' are a widespread and successful group of [[Ocean|marine]] [[Gastropod]] [[molluscs]]. The name means 'naked [[gills]]'. They are [[Animal shell|shell]]ess and uncoiled Gastropods, famous for their very brilliant colours. There are more than 3000 known [[species]]. Nudibranchs are one of the groups which are informally known as '''[[sea slug]]s'''. This is a term which includes other Gastropod groups which look similar to nudibranchs. Sea slugs is an informal term; it is not a [[monophyletic]] group. ==Biology == The body forms of nudibranchs vary greatly. They are ''opisthobranchs'', a [[clade]] which shed their shells after the [[larva]]l stage. Unlike most other gastropods they are ''[[bilateral symmetry|bilaterally symmetrical]]''. They have undergone secondary de[[torsion]].<ref>Uncoiling of the typical gastropod body shape, see garden [[snail]].</ref> Most species have [[Toxin|venomous]] [[appendage]]s on their sides. These are used to deter [[predator]]s. Many also have a simple gut and a mouth with a [[radula]]. Unusually for molluscs, they lack a [[mantle cavity]]. Nudibranchs are [[hermaphrodite]], and thus have a set of reproductive organs for both sexes, but they rarely fertilize themselves. Most nudibranchs are [[carnivore|carnivorous]