''Baeolidia variabilis'' 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 ...

, an aeolid nudibranch. It is 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 ...

Aeolidiidae Aeolidiidae, a family of aeolid nudibranchs, are a family of sea slugs, shell-less marine gastropod molluscs.Bouchet, P. (2014)''Aeolidiidae'' Gray, 1827.Accessed through: World Register of Marine Species on 2014-10-24 Most, or perhaps all, mem ...

found in the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

, the

Marshall Islands The Marshall Islands ( mh, Ṃajeḷ), officially the Republic of the Marshall Islands ( mh, Aolepān Aorōkin Ṃajeḷ),'' () is an independent island country and microstate near the Equator in the Pacific Ocean, slightly west of the Internati ...

and

Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...

, central Indo-Pacific Ocean.

Etymology

The specific name ''variabilis'' refers to the variable colour forms of this species.

Distribution

The holotype of this species was collected under coral rubble in shallow water at Medio Island,

Mindoro Mindoro is the seventh largest and eighth-most populous island in the Philippines. With a total land area of 10,571 km2 ( 4,082 sq.mi ) and has a population of 1,408,454 as of 2020 census. It is located off the southwestern coast of Luz ...

, Philippines, . Specimens from Papua New Guinea and

Kwajalein Atoll Kwajalein Atoll (; Marshallese: ) is part of the Republic of the Marshall Islands (RMI). The southernmost and largest island in the atoll is named Kwajalein Island, which its majority English-speaking residents (about 1,000 mostly U.S. civilia ...

, Marshall Islands were included in the description.

Description

There are apparently two colour forms of this species. In the Marshall Islands (animals of in length alive) the body of ''Baeolidia variabilis'' is translucent white with brown veins on the sides and a dense pattern of opaque white pigment over much of the dorsal surface. In the Philippines (animals of in length preserved) the white is absent and light ochre spots occur all over the body. The rhinophores are covered basally with sparse papillae which become numerous towards the tips. The cerata are rugose with opaque white pigment on the surface and translucent regions at the tips. In the Philippines animals the white pigment on the cerata was only in the basal and posterior regions of the cerata.Johnson, S., 2018
''Baeolidia variabilis''
Marshall Islands Sea Slugs, accessed 2018-11-23.

References

{{Taxonbar, from=Q21247080 Aeolidiidae Gastropods described in 2014