''Photocorynus'' is 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 ...

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 Linophrynidae, the leftvents. The only species in the genus is ''Photocorynus spiniceps''. ''Photocorynus'' was first proposed as a genus in 1925 by the English

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 ...

Charles Tate Regan Charles Tate Regan (1 February 1878 – 12 January 1943) was a British ichthyology, ichthyologist, working mainly around the beginning of the 20th century. He did extensive work on fish classification schemes. Born in Sherborne, Dorset, he was ...

when he described its only species, ''P. spiniceps''. 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 ...

of ''P. spiniceps'' was collected by the Danish research vessel '' Dana'' from the

Gulf of Panama The Gulf of Panama () is a gulf of the Pacific Ocean off the southern coast of Panama, where most of eastern Panama's southern shores adjoin it. The Gulf has a maximum width of , a maximum depth of and the size of . The Panama Canal connects the ...

at 7°15'N, 78°54'W, from a depth of around . 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 this taxon in the family Linophrynidae, within 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 ...

Ceratioidei Ceratioidei, the deep-sea anglerfishes or pelagic anglerfishes, is a suborder of marine ray-finned fishes, one of five suborders in the order Lophiiformes, the anglerfishes. These fishes are found in tropical and temperate seas throughout the wor ...

, the deep sea anglerfishes, of the

anglerfish The anglerfish are ray-finned fish in the order Lophiiformes (). Both the order's common name, common and scientific name comes from the characteristic mode of predation, in which a modified dorsal Fish fin#Ray-fins, fin ray acts as a Aggressiv ...

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 ...

Lophiiformes The anglerfish are ray-finned fish in the order Lophiiformes (). Both the order's common and scientific name comes from the characteristic mode of predation, in which a modified dorsal fin ray acts as a lure for prey (akin to a human angler, ...

. ''Photocorynus'' means "light club", an allusion to the

bioluminescent Bioluminescence is the emission of light during a chemiluminescence reaction by living organisms. Bioluminescence occurs in multifarious organisms ranging from marine vertebrates and invertebrates, as well as in some fungi, microorganisms inc ...

sac at the end of the short, club-like

illicium ''Illicium'' is a genus of flowering plants treated as part of the family Schisandraceae,

. 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 ...

, ''spiniceps'', means "spiny head", a reference to the robust spines on the sphenotic bone. The known mature male individuals are , smaller than any other mature fish and

vertebrate Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

; the females, however, reach a significantly larger size of up to . Numerous fish species have both sexes reaching maturity below . ''Photocorynus spiniceps'' has a circumglobal distribution in the Atlantic and Pacific Oceans. In the Atlantic Ocean it has been recorded from both sides between 32°N and 13°S. In the Pacific it has been recorded from Japan,

Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...

and the

specimen Specimen may refer to: Science and technology * Sample (material), a limited quantity of something which is intended to be similar to and represent a larger amount * Biological specimen or biospecimen, an organic specimen held by a biorepository f ...

s have been taken from depths betweem . Like most other deepsea

es, ''Photocorynus spiniceps'' lures its

prey Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not ki ...

into striking range using a

sac at the end of an

illicium ''Illicium'' is a genus of flowering plants treated as part of the family Schisandraceae,

, the highly modified first ray of the dorsal fin, and swallows the prey whole with the help of a distending jaw and a similarly distending stomach. Its prey can sometimes be as big as their own bodies. The male spends its life fused to its much larger female counterpart, therefore effectively turning her into a

hermaphrodite A hermaphrodite () is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic. The individuals of many ...

. The male has to bite the female in order to spend the rest of its life fused together. While the female takes care of swimming and eating, the male, with a large proportion of its body consisting of

testes A testicle or testis ( testes) is the gonad in all male bilaterians, including humans, and is homologous to the ovary in females. Its primary functions are the production of sperm and the secretion of androgens, primarily testosterone. The ...

, is charged with the task of aiding reproduction.

References

External links

Some records in the fish world
Linophrynidae Fish of the Philippines Deep sea fish Taxa named by Charles Tate Regan Fish described in 1925 Monotypic marine fish genera {{Lophiiformes-stub

See also

References

External links