''Lythrichthys'', the red deepwater scorpionfishes, 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, 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 botanical subfamily names with "-oideae", and zo ...

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 ) 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 ...

Scorpaenidae The Scorpaenidae (also known as scorpionfish) are a family (biology), family of mostly ocean, 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 ...

. They are native to the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

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 Universi ...

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 ...

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 "unisp ...

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 Honsh� ...

in Japan. ''L. eulabes'' was later placed in the genus ''

Setarches ''Setarches'' is a genus of deep-sea bristly scorpionfishes. Species There are currently two recognized species in this genus: * '' Setarches guentheri'' J. Y. Johnson, 1862 (Channelled rockfish) * '' Setarches longimanus'' (Alcock Alcock is ...

'' 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: 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 of all kno ...

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 Alcock is a surname. Notable people with the surname include: * Alfred William Alcock, British naturalist * C. W. Alcock, British sports administrator, creator of the FA Cup * Charles R. Alcock, American astronomer * Deborah Alcock, British auth ...

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 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 ...

, 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 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 ...

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 in bony fish that functions to modulate buoyancy, and thus allowing the fish to stay at desired water depth without having to maintain lift ...

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 s ...

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