''Plagiogeneion'' i is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

es belonging to 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 ...

Emmelichthyidae Emmelichthyidae is a small Family (biology), family of small to medium-sized Marine (ocean), marine ray-finned fishes known commonly as redbaits, rovers, bonnetmouths or rubyfishes. The Emmelichthyidae are poorly known even among researchers who ...

, the rovers, bonnetmouths or rubyfishes. The fishes in this genus are found in the southeastern Atlantic, Indian, and Pacific Oceans.

Taxonomy

''Plagiogeneion'' was first proposed as a

monospecific genus In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

in 1890 by the Scottish

explorer Exploration is the process of exploring, an activity which has some Expectation (epistemic), expectation of Discovery (observation), discovery. Organised exploration is largely a human activity, but exploratory activity is common to most organis ...

ornithologist Ornithology, from Ancient Greek ὄρνις (''órnis''), meaning "bird", and -logy from λόγος (''lógos''), meaning "study", is a branch of zoology dedicated to the study of birds. Several aspects of ornithology differ from related discip ...

, and

botanist Botany, also called plant science, is the branch of natural science and biology studying plants, especially Plant anatomy, their anatomy, Plant taxonomy, taxonomy, and Plant ecology, ecology. A botanist or plant scientist is a scientist who s ...

Henry Ogg Forbes Henry Ogg Forbes (30 January 1851 – 27 October 1932) was a Scottish explorer, ornithologist, and botanist. He also described a new species of spider, '' Thomisus decipiens''. Biography Forbes was the son of Rev Alexander Forbes M.A. (1821� ...

with ''Therapon rubiginosus'', which had been described in 1875 by Frederick W. Hutton from New Zealand, as its only species. The genus is classified in the small family Emmelichthyidae which is included in the

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Acanthuriformes Acanthuriformes is a large, diverse order of mostly marine ray-finned fishes, part of the Percomorpha clade. In the past, members of this clade were placed in the suborders Acanthuroidea and Percoidea of the order Perciformes, but this treatment ...

Etymology

''Plagiogeneion'' is a compound of ''plagios'', meaning "perpendicular", and ''geneion'', which means "jawed", an allusion to the almost vertical mouth of the

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

, ''P. rubiginosum''.

Species

There are currently five recognized species in this genus: * '' Plagiogeneion fiolenti'' Parin, 1991 * '' Plagiogeneion geminatum'' Parin, 1991 * '' Plagiogeneion macrolepis'' McCulloch, 1914 – bigscale rubyfish * ''

Plagiogeneion rubiginosum The rubyfish (''Plagiogeneion rubiginosum''), also known as the cosmopolitan rubyfish, red ruby or ruby rover, is a species of marine ray-finned fish, belonging to the family Emmelichthyidae, the rovers, bonnetmouths and rubyfishes. This species i ...

'' ( F. W. Hutton, 1875) – rubyfish * '' Plagiogeneion unispina'' Parin, 1991

Characteristics

''Plagiogeneion'' rubyfishes have a body which has a

standard length Fish measurement is the measuring of individual fish and various parts of fish anatomy, their anatomies, for data used in many areas of ichthyology, including Taxonomy (biology), taxonomy and fishery biology. Overall length Standard length (SL) is ...

of 2.8 to 3.6 times its depth. They have a continuous

dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...

which is only slightluy incised at the front of the soft-rayed portion of the fin. The final spines of both the dorsal and anal fins are not longer than the penultimate spines. They lack a fleshy ridge on the side of the

caudal peduncle Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...

and do not have a groove or fleshy protuberance on rear margin of the gill cavity. The upper spine on operculum is an obtuse flat point or developed as an acute spine. They have a small number of small sharp teeth at the front of the jaws and they may have similar teeth on the

vomer The vomer (; ) is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and articulates with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxillary bones. The vomer forms ...

and

palatine A palatine or palatinus (Latin; : ''palatini''; cf. derivative spellings below) is a high-level official attached to imperial or royal courts in Europe since Roman Empire, Roman times.

s. The

rubyfish The rubyfish (''Plagiogeneion rubiginosum''), also known as the cosmopolitan rubyfish, red ruby or ruby rover, is a species of marine ray-finned fish, belonging to the Family (biology), family Emmelichthyidae, the rovers, bonnetmouths and rubyfish ...

(''P. rubiginosum'') is the largest species, attaining a maximum published

total length Fish measurement is the measuring of individual fish and various parts of their anatomies, for data used in many areas of ichthyology, including taxonomy and fishery biology. Overall length Standard length (SL) is the length of a fish measured f ...

of , while the smallest is ''P. unispina'' at a maximum published standard length of .

References

{{Taxonbar, from=Q3005620 Emmelichthyidae Marine fish genera Taxa named by Henry Ogg Forbes