''Hermissenda emurai'' 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 ...

of brightly coloured

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 nudibranch, 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 ...

Facelinidae The Facelinidae are a Taxonomy (biology), taxonomic family (biology), family of colorful sea slugs. These are specifically aeolid nudibranchs. They are marine (ocean), marine gastropod molluscs.Bouchet, P. (2012). Facelinidae. Accessed through: W ...

.Lindsay, T. & Valdés, Á. (2016
''The Model Organism ''Hermissenda crassicornis'' (Gastropoda: Heterobranchia) Is a Species Complex.''
PLoS ONE 11(4): e0154265.

Distribution

This nudibranch was described from Niigata, Niigata Prefecture, Sea of Japan,

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

. Its distribution includes

Korea Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic o ...

and the Russian coast of the Japan Sea (although, no facts confirming distribution in Russia provided). It was (incorrectly) synonymised with ''

Hermissenda crassicornis ''Hermissenda crassicornis'', also known as the opalescent nudibranch or thick-horned nudibranch, is a species of brightly coloured, sea slug or nudibranch, a marine gastropod mollusc in the family Facelinidae.Rosenberg, G. (2011)''Hermissenda cr ...

'' in 1983.McDonald G. R. (1983) A review of the nudibranchs of the California coast. Malacologia 24: 114–276.

Description

The species grows to be about 50 mm, or about 2 inches.

References

{{Taxonbar, from=Q25095697 Facelinidae Gastropods described in 1937