''Johnsonina'' is a monospecific genus 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 ...

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 ...

Triacanthodidae, the spikefishes. The only species in the genus is ''Johnsonina eriomma'', the bullseye spikefish, which is found in the Western Atlantic Ocean.

Taxonomy

''Johnsonina'' 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 1934 by the American

ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 35,800 species of fish had been described as of March 2 ...

George S. Myers George Sprague Myers (February 2, 1905 – November 4, 1985) was an American ichthyologist who spent most of his career at Stanford University. He served as the editor of ''Stanford Ichthyological Bulletin'' as well as president of the American S ...

when he described its only species ''Johnsonina eriomma'', which he designated as its

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 ...

. Myers gave the type locality of ''J. eriomma'' as north of

Tobago Tobago, officially the Ward of Tobago, is an List of islands of Trinidad and Tobago, island and Regions and municipalities of Trinidad and Tobago, ward within the Republic of Trinidad and Tobago. It is located northeast of the larger islan ...

at 18°40'15'N, 60°50'15"W from a depth between . In 1968 James C. Tyler classified this genus in the

nominate Nomination is part of the process of selecting a candidate for either election to a public office, or the bestowing of an honor or award. A collection of nominees narrowed from the full list of candidates is a short list. Political office In th ...

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end botanical subfamily names with "-oideae", and zo ...

of the family Triacanthodidae, the

Triacanthodinae Triacanthodinae is a subfamily of marine ray-finned fishes belonging to the family Triacanthodidae, the spikefishes. This subfamily comprises nine genera and a total of nineteen species and all, except one species, are found in the tropical an ...

. It is the only species in that subfamily found in the Western Atlantic Ocean. The 5th edition of ''

Fishes of the World ''Fishes of the World'' is a standard reference for the systematics of fishes. It was first written in 1976 by the American ichthyologist Joseph S. Nelson (1937–2011). Now in its fifth edition (2016), the work is a comprehensive overview of t ...

'' classifies the family Triacanthodidae in the

suborder Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized ...

Triacanthoidei Triacanthoidei is a suborder of ray-finned fishes belonging to the order Tetraodontiformes, which includes the pufferfishes, triggerfishes and related taxa. These benthic fishes are mainly found in the Indian Ocean with some of the spikefishes fou ...

in the order Tetraodontiformes.

Etymology

Johnsonina suffixes the possessive ''-ina'' onto Johnson, honoring the

financier An investor is a person who allocates financial capital with the expectation of a future return (profit) or to gain an advantage (interest). Through this allocated capital the investor usually purchases some species of property. Types of in ...

Eldridge R. Johnson Eldridge Reeves Johnson (February 6, 1867 in Wilmington, Delaware – November 14, 1945 in Moorestown, New Jersey) was an American businessman and engineer who founded the Victor Talking Machine Company in 1901 and built it into the leading ...

who sponsored the Johnson-Smithsonian Deep-Sea Expedition of 1933 on which the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

was collected. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

''eriomma'' is a compound of ''eri'', meaning "very", and ''omma'', meaning "eye", an allusion to the large eyes and large eyespot.

Description

''Johnsonina'' has a deep, slightly compressed body with klarge eyes and a small mouth which opens at the front. There is a single series of conical teeth in each jaw. The gill slit is short and vertical positioned before the base of the

pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...

. The origin of the

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 ...

is to the rear of the top of the gill slit and contains 6 spines The first dorsal fin spine is long and robust, the spines decrease in size to the rear and they can be locked upright. There are typically 15 soft rays, rarely 14 or 15. The

anal fin 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 o ...

typically has 15, sometimes 14 or 16, branched soft rays, There is a large lockable spine in the

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral (belly) surface of fish, and are the lower of the only two sets of paired fins (the other being the laterally positioned pectoral fins). The pelvic fins are homologous to the hi ...

. The lower surface of the pelvis has a flat scales covered part which is long and tapering, widest at the front between spines of the pelvic fins. The skin is thick, rough and covered with many small scales, each scale having tiny spines. The color of the head and body is pale pinkish-brown, the upper half with orange -pink marbling, There is a large eye on the rear upper side which has a black centre enclosed in a thin orange ring which is enclosed within a wider white ring. This species reaches a length of .

Distribiution and habitat

''Johnsonina eriomma'' is distributed from the Bahamas, south through the Greater and Lesser Antilles, and the western Caribbean off Panama and Nicaragua. It is found at depths between over soft substrates.

References

{{Taxonbar, from=Q195875 Triacanthodinae Taxa named by George S. Myers Fish described in 1934 Monotypic marine fish genera