''Macrourus'' is a small benthopelagic genus of

rattail Grenadiers or rattails are generally large, brown to black gadiform marine fish of the subfamily Macrourinae, the largest subfamily of the family Macrouridae. Found at great depths from the Arctic to Antarctic, members of this subfamily are am ...

s from the family Macrouridae.

General features

The species in the genus ''Macrourus'' have large broad heads which are over four times as deep as it is long with a snout which varies from rounded to bluntly pointed, with a substantial modified spiny scale at its tip. They have a strong, suborbital ridge that extends onto preopercle and ends with a sharp point. The eyes have a diameter of around one third of the length of the head. It has small teeth which are set in in moderate to broad bands in the premaxilla which taper posteriorly and ending well short of the ends of the lips; the mandibular band is either 3 or 4 teeth wide at the symphysis, narrowing to 1 row posteriorly and extending to about the end of the lips. They have a serrated spiny dorsal fin ray; the

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two en ...

usually has 8 or 9 rays. The anus is at 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 ...

, there is no photophore. Their maximum size is probably around .

Habitat, distribution and biology

The species of ''Macrourus'' are found on the upper- to middle continental slope which are restricted to cold temperate and polar waters in both the North and South Atlantic as well as in the Southern Ocean. They are found at depths from around to greater than . They normally prefer temperatures of between , although one species, the Antarctic roughhead ('' Macrourus whitsoni''), has been collected at temperatures which were slightly below .

Fisheries

''Macrourus'' species are important food fishes in the North Atlantic and off the Patagonian coast of Argentina. They are normally considered as

bycatch Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juve ...

in the north eastern Atlantic but they are landed and the weight of catches landed between 1990 and 2015 varied from almost none to 4,000 tonnes.

Taxonomy and species

There is a controversy about the identification of the type species of this genus; ''Macrourus rupestris'' was named as the type species by

Bloch Bloch is a surname of German origin. Notable people with this surname include: A–F * (1859-1914), French rabbi *Adele Bloch-Bauer (1881-1925), Austrian entrepreneur *Albert Bloch (1882–1961), American painter * (born 1972), German motor journal ...

but this name is a

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

of ''

Coryphaenoides rupestris ''Coryphaenoides rupestris'' is a species of marine ray-finned fish in the family Macrouridae. Its common names include the rock grenadier, the roundnose grenadier and the roundhead rat-tail. In France it is known as ''grenadier de roche'' and in ...

''. In 1917 Jordan proposed that ''Macrourus berglax'' be designated the type species, but this also lacks clarity as

Sundevall Carl Jakob Sundevall (22 October 1801, Högestad – 2 February 1875) was a Swedish zoologist. Sundevall studied at Lund University, where he became a Ph.D. in 1823. After traveling to East Asia, he studied medicine, graduating as Doctor of Med ...

was of the view that the fish named as ''berglax'' by

Gunnerus Johan Ernst Gunnerus (26 February 1718 – 25 September 1773) was a Norwegian bishop and botanist. Gunnerus was born at Christiania. He was bishop of the Diocese of Nidaros from 1758 until his death and also a professor of theology at the Univer ...

was in fact ''C. rupestris'' and that ''M. berglax'' should be named ''M. fabricii''. This is still to be resolved by the

ICZN The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the I ...

. There are currently five recognized species in this genus: * ''

Macrourus berglax ''Macrourus berglax'', the roughhead grenadier or onion-eye grenadier, is a species of marine ray-finned fish in the family Macrouridae. It is a deep-water fish found in the Atlantic Ocean. Description The roughhead grenadier can reach a length ...

Lacépède Lacepede can refer to: * Bernard Germain de Lacépède (1756–1825), French naturalist and politician. * Lacepede Bay, a bay in South Australia. * Lacépède, Lot-et-Garonne, a ''commune'' in France * Lacepede Islands, a group of four islands in t ...

, 1801 (Roughhead grenadier) * ''

Macrourus caml ''Macrourus'' is a small benthopelagic genus of rattails from the family Macrouridae. General features The species in the genus ''Macrourus'' have large broad heads which are over four times as deep as it is long with a snout which varies f ...

'' P. J. McMillan, Iwamoto, A. L. Stewart & P. J. Smith, 2012 (Caml Grenadier)McMillan, P., Iwamoto, T., Stewart, A. & Smith, P.J. (2012). "A new species of grenadier, genus ''Macrourus'' (Teleostei, Gadiformes, Macrouridae) from the southern hemisphere and a revision of the genus." ''Zootaxa'' 3165: 1-24. * '' Macrourus carinatus'' ( Günther, 1878) (Ridge scaled rattail) * '' Macrourus holotrachys'' Günther, 1878 (Bigeye grenadier) * '' Macrourus whitsoni'' (

Regan The family name Regan, along with its cognates O'Regan, O Regan, Reagan, and O'Reagan, is an Anglicized form of the Irish surname Ó Riagáin or Ó Ríogáin, from Ua Riagáin. The meaning is likely to have originated in ancient Gaelic ''ri'' ...

, 1913) (Whitson's grenadier)

References

Macrouridae {{Gadiformes-stub