''Sternoptyx'' is an

ocean The ocean (also the sea or the world ocean) is the body of salt water that covers approximately 70.8% of the surface of Earth and contains 97% of Earth's water. An ocean can also refer to any of the large bodies of water into which the wo ...

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or h ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

which belongs in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Sternoptychidae The marine hatchetfishes or deep-sea hatchetfishes as well as the related bottlelights, pearlsides and constellationfishes are small deep-sea ray-finned fish of the stomiiform family Sternoptychidae. They are not closely related to and sh ...

. This is the

type genus In biological taxonomy, the type genus is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal ...

of the Sternoptychidae, as well as the

marine hatchetfish Marine hatchetfishes or deep-sea hatchetfishes are small deep-sea mesopelagic ray-finned fish of the stomiiform subfamily Sternoptychinae. They should not be confused with the freshwater hatchetfishes, which are not particularly closely related T ...

subfamily Sternoptychinae. ''Sternoptyx'' have silvery, high, and laterally compressed bodies and large, non-telescopic eyes. They are all relatively small, with even the largest species (''S. pseudobscura'' and ''S. pseudodiaphana'') not exceeding standard length.

Species

There are currently four recognized species in this genus: * '' Sternoptyx diaphana'' Hermann, 1781 (Diaphanous hatchetfish) * '' Sternoptyx obscura''

Garman Garman is a surname or first name. Notable people with the name include: Sports * Ann Garman, All-American Girls Professional Baseball League player * Judi Garman (born 1954), American softball coach * Mike Garman (born 1949), American baseball pla ...

, 1899 * '' Sternoptyx pseudobscura'' R. C. Baird, 1971 (Highlight hatchetfish) * '' Sternoptyx pseudodiaphana'' Borodulina, 1977 (False oblique hatchetfish)

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s of this genus show that they have existed at least since the

Early Oligocene The Rupelian is, in the geologic timescale, the older of two ages or the lower of two stages of the Oligocene Epoch/ Series. It spans the time between . It is preceded by the Priabonian Stage (part of the Eocene) and is followed by the Chattian ...

, about 30

million years ago The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago) ...

. (2002): 'Sternoptyx'' ''In:'' A compendium of fossil marine animal genera. ''Bulletins of American Paleontology'' 364: 560
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References

Sternoptychidae Extant Rupelian first appearances Ray-finned fish genera Taxa named by Johann Hermann Rupelian genus first appearances {{Stomiiformes-stub