''Goniobranchus setoensis'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

sea slug Sea slug is a common name for some Marine biology, marine invertebrates with varying levels of resemblance to terrestrial Slug, slugs. Most creatures known as sea slugs are gastropods, i.e. they are Sea snail, sea snails (marine gastropod moll ...

, 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 familie ...

nudibranch Nudibranchs () are a group of soft-bodied marine gastropod molluscs, belonging to the order Nudibranchia, that shed their shells after their larval stage. They are noted for their often extraordinary colours and striking forms, and they have b ...

, a marine

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

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 setoensis'' for many years before it was transferred to the genus ''

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

'' 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

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

. It has been confused with ''

Goniobranchus decorus ''Goniobranchus decorus'' 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 decora'' for many years before it was transferred to ...

'' and many records of ''G. decorus'' are in fact misidentifications. It occurs in the central Indo-Pacific region from Japan to Sri Lanka, and as far east as the Marshall Islands and Kiribati. The two species are

sympatric In biology, two closely related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter each other. An initially interbreeding population that splits into two or more distinct spe ...

in the Marshall Islands.Scott Johnson, 2015
''Goniobranchus decorus'' (Pease, 1860).
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 and a line running from between the

rhinophore A rhinophore is one of a pair of Chemoreceptor, chemosensory club-shaped, rod-shaped or ear-like structures which are the most prominent part of the external head anatomy in sea slugs, Marine (ocean), marine gastropod opisthobranch mollusks suc ...

s to the middle of the back where it divides to pass around the gills in a loop. Outside the outer white line is a row or double row of purple spots which never have a halo of white around them. There are small white spots along the mantle edge. The tips of the

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 setoensis'' feeds on

sponges Sponges or sea sponges are primarily marine invertebrates of the animal phylum Porifera (; meaning 'pore bearer'), a basal clade and a sister taxon of the diploblasts. They are sessile filter feeders that are bound to the seabed, and ar ...

of the family Aplysillidae.

References

{{Taxonbar, from=Q13645404 Chromodorididae Gastropods described in 1938