''Gymnapogon'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of fish 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 ...

Apogonidae Cardinalfishes are a family, Apogonidae, of ray-finned fishes found in the Atlantic, Indian, and Pacific Oceans; they are chiefly marine, but some species are found in brackish water and a few (notably ''Glossamia'') are found in fresh water. A h ...

. They are native to the Indo-West Pacific and central

Pacific Oceans The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

, where they occur in

reef A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes— deposition of sand, wave erosion planing down rock out ...

s and nearby habitat types. These

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 ...

are usually no more than 5 centimeters long and have semitransparent bodies without

scales Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number w ...

. The genus name is a compound noun formed by combining the Greek ''gymnos'' meaning "naked", referring to the lack of scales in the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

, ''Gymnapogon japonicus'', and '' Apogon'', the type genus of the Apogonidae. One species, the B-spot cardinalfish (''Gymnapogon urospilotus''), is notable for its larvae being rather large, conspicuous and fast-swimming.

Species

There are currently 9 recognized species in this genus:Mabuchi, K., Fraser, T.H., Song, H., Azuma, Y. & Nishida, M. (2014)
Revision of the systematics of the cardinalfishes (Percomorpha: Apogonidae) based on molecular analyses and comparative reevaluation of morphological characters.
''Zootaxa, 3846 (2): 151–203.'' * '' Gymnapogon africanus''

J. L. B. Smith James Leonard Brierley Smith (26 September 1897 – 8 January 1968) was a South African ichthyologist, organic chemist, and university professor. He was the first to identify a taxidermied fish as a coelacanth, at the time thought to be long ex ...

, 1954 (Crystal cardinalfish) * '' Gymnapogon annona'' ( Whitley, 1936) (Naked cardinalfish) * '' Gymnapogon foraminosus'' ( S. Tanaka (I), 1915) * '' Gymnapogon janus'' T. H. Fraser, 2016 Fraser, T.H. (2016): A new species of cardinalfish (''Gymnapogon'', Gymnapogonini, Apogonidae, Percomorpha) from the Philippines. ''Zootaxa, 4107 (3): 431-438.'' * '' Gymnapogon japonicus''

Regan The family name Regan, along with its cognates O'Regan, O Regan, Reagan, and O'Reagan, is an Anglicized form of the Irish surname Ó Riagáin or Ó Ríogáin, from Ua Riagáin. The meaning is likely to have originated in ancient Gaelic ''ri'' ...

, 1905 * '' Gymnapogon melanogaster'' Gon & Golani, 2002 * '' Gymnapogon philippinus'' ( Herre, 1939) (Philippines cardinalfish) * '' Gymnapogon urospilotus'' Lachner, 1953 (B-spot cardinalfish) * '' Gymnapogon vanderbilti'' ( Fowler, 1938) (Vanderbilt's cardinalfish)

References

Pseudaminae Marine fish genera Taxa named by Charles Tate Regan {{Kurtiformes-stub