''Goniobranchus decorus'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

sea slug 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 (marine gastropod mollusks) that over evolutionary t ...

, a

dorid ''Doridacea'' is a taxonomic grouping of dorid nudibranchs, shell-less marine gastropod mollusks.Bouchet P. & Rocroi J.-P. (Ed.); Frýda J., Hausdorf B., Ponder W., Valdes A. & Warén A. 2005''Classification and nomenclator of gastropod families ...

nudibranch 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 matc ...

, a marine

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Chromodorididae 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.” ...

''.

Taxonomic history

This species was known as ''Chromodoris decora'' for many years before it was transferred to the genus ''

Goniobranchus ''Goniobranchus'' is a genus of sea slugs, dorid nudibranchs, shell-less marine gastropod molluscs in the family Chromodorididae.Bouchet, P.; Caballer, M. (2012)''Goniobranchus''.Accessed through: World Register of Marine Species on 2012-04-22 ...

'' on the basis of molecular (DNA) evidence in 2012.Johnson R.F. & Gosliner T.M. (2012
''Traditional taxonomic groupings mask evolutionary history: A molecular phylogeny and new classification of the chromodorid nudibranchs.''
PLoS ONE 7(4): e33479.

Distribution

This species was described from

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...

. It has been confused with ''

Goniobranchus setoensis ''Goniobranchus setoensis'' is a species of sea slug, a dorid nudibranch, a marine gastropod mollusc in the family ''Chromodorididae''. Taxonomic history This species was known as ''Chromodoris setoensis'' for many years before it was transferr ...

'' and many records are therefore misidentifications. It occurs in the western Pacific Ocean from Hawaii to the Marshall Islands and New Caledonia. The two species are sympatric in the Marshall Islands.Scott Johnson (2015
''Goniobranchus decorus''.
n/nowiki> Underwater Kwajalein

Description

The body of this chromodorid nudibranch is translucent white with opaque white lines, purple spots and a sub-surface margin of orange-red. There is usually a white line around the centre of the back which can extend into patches of white running towards the midline. The midline itself is usually marked with white patches or a broad white stripe with diffuse edges. Within the white are a few purple spots and these usually form a line down the centre of the back, always with a halo of white around them. The tips of the

rhinophore 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 har ...

s and the outer part of the gills is white.Rudman, W.B., 2007 (September 13
''Chromodoris decora'' (Pease, 1860).
n/nowiki> Sea Slug Forum. Australian Museum, Sydney. (Description includes both ''G. decorus'' and ''G. setoensis'')

Ecology

''Goniobranchus decorus'' feeds on

sponges Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through ...

of the family Aplysillidae including ''

Chelonaplysilla violacea ''Chelonaplysilla violacea'' is a species of sponge found mainly in New Zealand, but have been reported on both sides of the Pacific Ocean, including areas such as the Indo-Pacific, the United Arab Emirates, the Persian Gulf, Australia, and Hawa ...

''.

References

{{Taxonbar, from=Q13645395 Chromodorididae Gastropods described in 1860