''Lythrichthys'', the red deepwater scorpionfishes, 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 marine ray-finned fish, belonging to the

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 subfamily botanical names with "-oideae", and zoologi ...

Setarchinae Setarchinae, the deep-sea bristly scorpionfishes, is a small subfamily of deep-sea ray-finned fishes, it is part of the family Scorpaenidae. They are small marine fishes, growing up to 25 cm, and are found in tropical and subtropical waters ...

, the deep-sea bristly scorpionfishes, part of 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 ...

Scorpaenidae The Scorpaenidae (also known as scorpionfish) are a family of mostly marine fish that includes many of the world's most venomous species. As their name suggests, scorpionfish have a type of "sting" in the form of sharp spines coated with venom ...

. They are native to the

Pacific Ocean 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 ...

Taxonomy

''Lythrichthys'' was first described as a genus in 1904 by the American ichthyologists

David Starr Jordan David Starr Jordan (January 19, 1851 – September 19, 1931) was the founding president of Stanford University, serving from 1891 to 1913. He was an ichthyologist during his research career. Prior to serving as president of Stanford Univer ...

and

Edwin Chapin Starks Edwin Chapin Starks (born in Baraboo, Wisconsin on January 25, 1867; died December 29, 1932) was an ichthyologist most associated with Stanford University. He was known as an authority on the osteology of fish. He also did studies of fish of the Pu ...

as a

monotypic 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 "unispec ...

genus for ''Lythrichthys eulabes'' which they described with a type locality given as off Ose Point in

Suruga Bay Suruga Bay (駿河湾, ''Suruga-wan'') is a bay on the Pacific coast of Honshū in Shizuoka Prefecture, Japan. It is situated north of a straight line from Omaezaki Point to Irōzaki Point at the tip of the Izu Peninsula and surrounded by Honshū ...

in Japan. ''L. eulabes'' was later placed in the genus '' Setarches'' and ''Lythrichthys'' became a synonym of that taxon. However, in 2021 Wada, Kai & Motomura resurrected the genus, added ''L. cypho'' (which had been treated as a synonym of''Setarches longimanus''), as well as ''L. longimanus'', and described two new species. This left the channelled rockfish (''Setarches guentheri'') as the only species in the now monotypic ''Setarches'' As of January 2022 this change has been accepted by

Catalog of Fishes Catalog of Fishes is a comprehensive on-line database and reference work on the scientific names of fish species and genera. It is global in its scope and is hosted by the California Academy of Sciences. It has been compiled and is continuously up ...

. The genus name is a compound of ''lythrum'', which means "gore", alluding to red colour of the body of living ''L. eulabes'', and ''ichthys'',

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

for "fish".

Species

The following 5 species are classified within the genus ''Lythrichthys'': * '' Lythrichthys cypho'' ( Fowler, 1938) (Dwarf red deepwater scorpionfish) * '' Lythrichthys dentatus'' Wada, Kai & Motomura 2021 (Gap-toothed red deepwater scorpionfish) * '' Lythrichthys eulabes'' Jordan & Starks 1904 (Jordan's red deepwater scorpionfish) * '' Lythrichthys grahami'' Wada, Kai & Motomura 2021 (Graham's red deepwater scorpionfish) * '' Lythrichthys longimanus'' ( Alcock 1894) (Red deepwater scorpionfish)

Characteristics

''Lythrichthys'' deepwater red scorpionfishes are characterised by typically having 3 spines and 5 soft rays in the

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

, although there may be as few as 4 or as many as 6 anal soft rays/ they have 7-12 predorsal scales. The body depth at the origin of the pelvic fin is 29.1% to 38.6% of the

standard length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish m ...

and the interorbital area has a width at the vertical midline of eye of 8.1% to 12.9% of the standard length. The snout, dorsal and ventral surface of head have no scales. No less than 75% of the lateral surface of premaxilla is covered by a well-developed lip. the first lacrimal spine is well developed and is roughly the same length as the second and third spines. There are 5 preopercular spines, with the second being much less well developed than the first and third which are also much longer than the fourth and fifth spines which are subequal in length. The tip of the first lacrimal spine just extends over the upper lip< the scales on the thorax and abdomen are clearly embedded in the skin. they have a well developed

swim bladder The swim bladder, gas bladder, fish maw, or air bladder is an internal gas-filled Organ (anatomy), organ that contributes to the ability of many bony fish (but not cartilaginous fish) to control their buoyancy, and thus to stay at their curren ...

Distribution

''Lythrichthys'' deepwater red scorpionfishes are found in the

Indo-West Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

as far north as Japan and south to Australia and west as far as Fiji.

References

{{Taxonbar, from=Q107271709 Setarchinae Taxa named by David Starr Jordan Taxa named by Edwin Chapin Starks Ray-finned fish genera