''Hypselodoris variobranchia'' 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 ...

or dorid

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 Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

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.” ...

Distribution

The holotype of this nudibranch was collected at 30 m depth from Aphol's Rock, Maricaban Island, Tingloy,

Batangas Province Batangas, officially the Province of Batangas ( tl, Lalawigan ng Batangas ), is a province in the Philippines located in the Calabarzon region on Luzon. Its capital is the city of Batangas, and is bordered by the provinces of Cavite and Laguna ...

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, . It is a common and widespread species which has been reported from

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

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;

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;

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and

Okinawa is a prefecture of Japan. Okinawa Prefecture is the southernmost and westernmost prefecture of Japan, has a population of 1,457,162 (as of 2 February 2020) and a geographic area of 2,281 km2 (880 sq mi). Naha is the capital and largest city ...

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but frequently mistaken for ''

Hypselodoris bullocki ''Hypselodoris bullockii'' is a species of colourful sea slug or dorid nudibranch, a marine gastropod mollusc in the family Chromodorididae. ''Hypselodoris bullockii'' is quite pale purple in colour. It has been mistaken for a number of other sp ...

'' or '' Hypselodoris apolegma''.

Description

''Hypselodoris variobranchia'' has a deep purple body with a broad solid white border to the mantle. The bulb of the

rhinophores 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 hares ...

is orange, with purple sheaths. The gills may be orange or deep purple. There is a tall gill pocket which is also deep purple in colour. This species has frequently been reported as ''Hypselodoris bullocki''.Rudman W. B., 199
''Hypselodoris bullocki'' (Collingwood, 1881) - Page 1, Fig E.
In: Sea slug forum. Sydney: Australian Museum. This is a large nudibranch, reaching 50 mm in length.

References

{{Taxonbar, from=Q60183437 Chromodorididae Gastropods described in 2018