The eelpouts are the

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 ...

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 ...

Zoarcidae. As the common name suggests, they are somewhat

eel Eels are ray-finned fish belonging to the order Anguilliformes (), which consists of eight suborders, 19 families, 111 genera, and about 800 species. Eels undergo considerable development from the early larval stage to the eventual adult stage ...

-like in appearance. All of the roughly 300

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

are marine and mostly bottom-dwelling, some at great depths. Eelpouts are predominantly found in the Northern Hemisphere. The arctic, north pacific and north Atlantic oceans have the highest concentration of species, however species are found around the globe. They are conventionally placed in the "

perciform Perciformes (), also called the Percomorpha or Acanthopteri, is an order or superorder of ray-finned fish. If considered a single order, they are the most numerous order of vertebrates, containing about 41% of all bony fish. Perciformes means " ...

" assemblage; in fact, the Zoarcoidei seem to be specialized members of the Gasterosteiformes-

Scorpaeniformes The Scorpaeniformes are a diverse order of ray-finned fish, including the lionfishes and sculpins, but have also been called the Scleroparei. It is one of the five largest orders of bony fishes by number of species, with over 1,320. They are ...

group of

Acanthopterygii Acanthopterygii (meaning "spiny finned one") is a superorder of bony fishes in the class Actinopterygii. Members of this superorder are sometimes called ray-finned fishes for the characteristic sharp, bony rays in their fins; however this name i ...

. The largest member of the family is '' Zoarces americanus'', which may reach 1.1 m in length. Other notable genera include '' Lycodapus'' and '' Gymnelus''.

Taxonomy

The eelpout family was first proposed as the family Zoarchidae in 1839 by the English naturalist William John Swainson but the spelling was changed to Zoarcidae after the spelling of the genus Zoarces was corrected by Theodore Gill in 1861. The 5th edition of '' Fishes of the World'' classifies this family within the suborder Zoarcoidei, within the order Scorpaeniformes. Other authorities classify this family in the

infraorder Order ( la, ordo) 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 ...

Zoarcales wihin the suborder Cottoidei of the

Perciformes Perciformes (), also called the Percomorpha or Acanthopteri, is an order or superorder of ray-finned fish. If considered a single order, they are the most numerous order of vertebrates, containing about 41% of all bony fish. Perciformes means ...

because removing the Scorpaeniformes from the Perciformes renders that taxon non monophyletic. ''Fishes of the World'' mentions four subfamilies but does not assign genera to the subfamilies but these were set out in Anderson and Federov's Annotated Checklist and this has been followed by '' FishBase'' and ''

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 u ...

''.

Subfamilies and genera

The eelpouts are classified into four subfamilies and 61 genera with around 300 species: * subfamily Gymnelinae

Gill A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

, 1863 ** '' Andriashevia'' Fedorov & Neelov, 1978 ** '' Barbapellis'' Iglésias, Dettai & Ozouf-Costaz, 2012 ** '' Bilabria'' Schmidt, 1936 ** '' Davidijordania'' Popov, 1931 ** '' Ericandersonia'' Shinohara & Sakurai, 2006 ** '' Gymnelopsis'' Soldatov, 1922 ** '' Gymnelus'' Reinhardt 1834 ** '' Hadropareia'' Schmidt, 1904 ** '' Krusensterniella'' Schmidt, 1904 ** '' Magadanichthys'' Shinohara, Nazarkin & Chereshnev, 2006 ** '' Melanostigma'' Günther, 1881 ** '' Nalbantichthys'' Schultz, 1967 ** '' Opaeophacus'' Bond &

Stein Stein is a German, Yiddish and Norwegian word meaning "stone" and "pip" or "kernel". It stems from the same Germanic root as the English word stone. It may refer to: Places In Austria * Stein, a neighbourhood of Krems an der Donau, Lower Aust ...

, 1984 ** '' Puzanovia'' Fedorov, 1975 ** '' Seleniolycus''

Anderson Anderson or Andersson may refer to: Companies * Anderson (Carriage), a company that manufactured automobiles from 1907 to 1910 * Anderson Electric, an early 20th-century electric car * Anderson Greenwood, an industrial manufacturer * Anderson ...

, 1988 * subfamily

Lycodinae Lycodinae is a subfamily of marine ray-finned fish belonging to the family Zoarcidae, the eelpouts. These eelpouts are found are in all the world's oceans, with a number of species being found off southern South America. Taxonomy Lycodinae was f ...

Gill, 1861 ** '' Aiakas'' Gosztonyi, 1977 ** '' Argentinolycus'' Matallanas & Corbella, 2012 ** '' Austrolycus'' Regan, 1913 ** '' Bellingshausenia'' Matallanas, 2009 ** '' Bentartia'' Matallanas, 2010 ** '' Bothrocara'' Bean, 1890 ** '' Bothrocarina'' Suvorov, 1935 ** '' Crossostomus'' Lahille, 1908 ** '' Dadyanos'' Whitley, 1951 ** '' Derepodichthys'' Gilbert, 1896 ** '' Dieidolycus'' Anderson, 1988 ** '' Eucryphycus'' Anderson, 1988 ** '' Exechodontes'' DeWitt, 1977 ** '' Gosztonyia'' Matallanas, 2009 ** '' Hadropogonichthys'' Fedorov, 1982 ** '' Iluocoetes'' Jenyns, 1842 ** '' Japonolycodes'' Shinohara, Sakurai & Machida, 2002 ** '' Letholycus'' Anderson, 1988 ** '' Lycenchelys'' Gill, 1884 ** '' Lycodapus'' Gilbert, 1890 ** '' Lycodes'' Reinhardt, 1831 ** '' Lycodichthys'' Pappenheim, 1911 ** '' Lycodonus'' Goode & Bean, 1883 ** '' Lycogrammoides'' Soldatov & Lindberg, 1928 ** '' Lyconema'' Gilbert, 1896 ** '' Maynea'' Cunningham, 1871 ** '' Notolycodes'' Gosztonyi, 1977 ** '' Oidiphorus'' McAllister & Rees 1964 ** '' Ophthalmolycus'' Regan, 1913 ** '' Pachycara'' Zugmayer. 1911 ** '' Patagolycus'' Matallanas & Corbella, 2012 ** '' Petroschmidtia'' Taranetz & Andriashev, 1934 ** '' Phucocoetes'' Jenyns, 1842 ** '' Piedrabuenia'' Gosztonyi, 1977 ** '' Plesienchelys'' Anderson, 1988 ** '' Pogonolycus'' Norman, 1937 ** '' Pyrolycus'' Machida & Hashimoto, 2002 ** '' Santelmoa'' Matallanas, 2010 ** '' Taranetzella'' Andriashev, 1952 ** '' Thermarces'' Rosenblatt & Cohen, 1986 ** '' Zestichthys''

Jordan Jordan ( ar, الأردن; tr. ' ), officially the Hashemite Kingdom of Jordan,; tr. ' is a country in Western Asia. It is situated at the crossroads of Asia, Africa, and Europe, within the Levant region, on the East Bank of the Jordan Rive ...

& Hubbs, 1925 * subfamily Lycozarcinae Andriashev, 1939 ** '' Lycozoarces'' Popov, 1935 * subfamily Zoarcinae Swainson, 1839 ** ''

Zoarces ''Zoarces'' is a genus of marine ray-finned fishes belonging to the family (biology), family Zoarcidae, the eelpouts. It is the only genus in the subfamily Zoarcinae. These eelpouts are found in the northern Atlantic and northern Pacific Oceans. ...

'' Cuvier 1829

Characteristics

The body of eelpouts is relatively elongated and laterally compressed. Their heads are relatively small and ovoid. Juveniles have a more rounded snout and relatively larger eye than adults. Their scales are absent or very small. The

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal c ...

and

anal Anal may refer to: Related to the anus *Related to the anus of animals: ** Anal fin, in fish anatomy ** Anal vein, in insect anatomy ** Anal scale, in reptile anatomy *Related to the human anus: ** Anal sex, a type of sexual activity involving s ...

fins are continuous down their bodies up to their caudal fin. They produce the pigment

vivianite Vivianite () is a hydrated iron phosphate mineral found in a number of geological environments. Small amounts of manganese Mn2+, magnesium Mg and calcium Ca may substitute for iron Fe2+ in the structure.Gaines et al (1997) Dana’s New Minera ...

, which turns their bones green. This feature has no apparent evolutionary function and is harmless. Overall, there is no

sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most an ...

Biology

Little is known about eelpout populations because they often slip through nets in sampling studies, and because some species live in inaccessibly deep habitats. Species for which trophic ecology has been documented are typically, if not always, benthic scavengers or predators. At least one species has also adapted to able to breathe air when out of water.

Timeline

ImageSize = width:1000px height:auto barincrement:15px PlotArea = left:10px bottom:50px top:10px right:10px Period = from:-65.5 till:10 TimeAxis = orientation:horizontal ScaleMajor = unit:year increment:5 start:-65.5 ScaleMinor = unit:year increment:1 start:-65.5 TimeAxis = orientation:hor AlignBars = justify Colors = #legends id:CAR value:claret id:ANK value:rgb(0.4,0.3,0.196) id:HER value:teal id:HAD value:green id:OMN value:blue id:black value:black id:white value:white id:cenozoic value:rgb(0.54,0.54,0.258) id:paleogene value:rgb(0.99,0.6,0.32) id:paleocene value:rgb(0.99,0.65,0.37) id:eocene value:rgb(0.99,0.71,0.42) id:oligocene value:rgb(0.99,0.75,0.48) id:neogene value:rgb(0.999999,0.9,0.1) id:miocene value:rgb(0.999999,0.999999,0) id:pliocene value:rgb(0.97,0.98,0.68) id:quaternary value:rgb(0.98,0.98,0.5) id:pleistocene value:rgb(0.999999,0.95,0.68) id:holocene value:rgb(0.999,0.95,0.88) BarData= bar:eratop bar:space bar:periodtop bar:space bar:NAM1 bar:NAM2 bar:space bar:period bar:space bar:era PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 shift:(7,-4) bar:periodtop from: -65.5 till: -55.8 color:paleocene text:

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...

from: -55.8 till: -33.9 color:eocene text:

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

from: -33.9 till: -23.03 color:oligocene text: Oligocene from: -23.03 till: -5.332 color:miocene text:

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

from: -5.332 till: -2.588 color:pliocene text: Plio. from: -2.588 till: -0.0117 color:pleistocene text: Pleist. from: -0.0117 till: 0 color:holocene text: H. bar:eratop from: -65.5 till: -23.03 color:paleogene text: Paleogene from: -23.03 till: -2.588 color:neogene text: Neogene from: -2.588 till: 0 color:quaternary text: Q. PlotData= align:left fontsize:M mark:(line,white) width:5 anchor:till align:left color:pliocene bar:NAM1 from: -5.332 till: 0 text: Anarhichas color:pleistocene bar:NAM2 from: -2.588 till: 0 text:

Anarrhichthys The wolf eel (''Anarrhichthys ocellatus'') is a species of marine ray-finned fish belonging to the family Anarhichadidae, the wolf fishes. It is found in the North Pacific Ocean. Despite its common name and resemblance, it is not a true eel. It ...

PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 bar:period from: -65.5 till: -55.8 color:paleocene text:

from: -55.8 till: -33.9 color:eocene text:

from: -33.9 till: -23.03 color:oligocene text: Oligocene from: -23.03 till: -5.332 color:miocene text:

from: -5.332 till: -2.588 color:pliocene text: Plio. from: -2.588 till: -0.0117 color:pleistocene text: Pleist. from: -0.0117 till: 0 color:holocene text: H. bar:era from: -65.5 till: -23.03 color:paleogene text: Paleogene from: -23.03 till: -2.588 color:neogene text: Neogene from: -2.588 till: 0 color:quaternary text: Q.

References

{{Taxonbar, from=Q300929 * Ray-finned fish families