Threadfins are silvery grey perciform fish of the family Polynemidae. Found in tropical to subtropical waters throughout the world, the threadfin family contains eight

genera 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 nomenclat ...

and about 40 species. An unrelated species sometimes known by the name threadfin, ''Alectis indicus'', is properly the

Indian threadfish The Indian threadfish (''Alectis indica''), also known as the Indian threadfin, diamond trevally, mirror fish or plumed trevally, is a large species of coastal marine fish of the jack family, Carangidae. The species is widespread in the waters ...

(family Carangidae). Ranging in length from in the

dwarf threadfin The dwarf paradise fish (''Parapolynemus verekeri''), also known as the streamer threadfin or streamered tasselfish, is a species of ray-finned fish from a family Polynemidae, the threadfins. It is the only species in the genus ''Parapolynemus'' ...

(''Parapolynemus verekeri'') to in

fourfinger threadfin ''Eleutheronema tetradactylum'', the fourfinger threadfin, is a species of marine ray-finned fish, a threadfin from the family Polynemidae which occurs in the Indian and western Pacific Ocean. Description ''Eleutheronema tetradactylum'' has two ...

(''Eleutheronema tetradactylum'') and

giant African threadfin The giant African threadfin (''Polydactylus quadrifilis'') is a species of ray-finned fish from the threadfin family Polynemidae. It is found in the eastern Atlantic Ocean off the west coast of Africa. Description The giant African threadfin is, ...

(''Polydactylus quadrifilis''), threadfins are both important to commercial

fisheries Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, both ...

as a food fish, and popular among anglers. Their habit of forming large schools makes the threadfins a reliable and economic catch.

Description

Their bodies are

elongated Elongation may refer to: * Elongation (astronomy) * Elongation (geometry) * Elongation (plasma physics) * Part of transcription of DNA into RNA of all types, including mRNA, tRNA, rRNA, etc. * Part of translation (biology) of mRNA into proteins ...

and

fusiform Fusiform means having a spindle-like shape that is wide in the middle and tapers at both ends. It is similar to the lemon-shape, but often implies a focal broadening of a structure that continues from one or both ends, such as an aneurysm on a b ...

, with spinous and soft dorsal fins widely separated. Their tail fins are large and deeply forked, indicating speed and agility. The mouth is large and

inferior Inferior may refer to: * Inferiority complex * An Anatomical terms of location#Superior and inferior, anatomical term of location * Inferior angle of the scapula, in the human skeleton *Inferior (book), ''Inferior'' (book), by Angela Saini * ''The ...

; a blunt snout projects far ahead. The jaws and palate possess bands of villiform (fibrous) teeth. Their most distinguishing feature is their pectoral fins: they are composed of two distinct sections, the lower of which consists of three to seven long, thread-like independent rays. ''Polynemus'' species may have up to 15 of these modified rays. In some species, such as the royal threadfin (''

Pentanemus quinquarius The royal threadfin (''Pentanemus quinquarius'') is a species of ray-finned fish, a threadfin from the family Polynemidae, the threadfins. It is found in the eastern Atlantic Ocean along the western coast of Africa. Description The royal threadf ...

''), the thread-like rays may extend well past the tail fin. This feature explains both the common name threadfin and the family name Polynemidae, from the Greek ''poly'' meaning "many" and ''nema'' meaning "filament." Similar species, such as the mullets (family Mugilidae) and milkfish (family

Chanidae Chanidae is a family of fishes which has a number of fossil genera and one monotypic extant genus which contains the milkfish (''Chanos chanos''). Taxonomy The family Chanidae is subdivided into two subfamilies, the Rubiesichthyinae, which comp ...

), can be easily distinguished from threadfins by their lack of filamentous pectoral rays.

Distribution and habitat

Threadfins frequent open, shallow water in areas with muddy, sandy, or silty bottoms; they are rarely seen at reefs. Their pectoral rays are thought to serve as tactile structures, helping to find prey within the sediments. Noted for being

euryhaline Euryhaline organisms are able to adapt to a wide range of salinities. An example of a euryhaline fish is the molly (''Poecilia sphenops'') which can live in fresh water, brackish water, or salt water. The green crab (''Carcinus maenas'') is an e ...

, threadfins can tolerate a wide range of

salinity Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal ...

levels. This attribute allows threadfins to enter estuaries and even rivers. They feed primarily on

crustacea Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean gro ...

ns and smaller fish.

Reproduction

Presumed to be pelagic spawners, threadfins probably release many tiny, buoyant eggs into the water column, which then become part of the plankton. The eggs float freely with the currents until hatching.

Cuisine

Threadfin has been used to create crab stick.

Mariculture

In Hawaii, sixfinger threadfins are the subject of commercial open-ocean cage

mariculture Mariculture or marine farming is a specialized branch of aquaculture (which includes freshwater aquaculture) involving the cultivation of marine organisms for food and other animal products, in enclosed sections of the open ocean ( offshore mari ...

Genera and species

Elegant paradiseus fish Polynemus multifilis

The species in eight genera are: * Genus '' Eleutheronema'' ** ''

Eleutheronema rhadinum ''Eleutheronema'' is a genus of marine ray-finned fish from the family Polynemidae, the threadfins. These fishes occur in the Indian Ocean and the western Pacific Ocean. Species The following species are classified within the genus ''Eleuther ...

'' ( Jordan & Evermann, 1902) (East Asian fourfinger threadfin) ** '' Eleutheronema tetradactylum'' (Shaw, 1804) (Fourfinger threadfin) ** '' Eleutheronema tridactylum'' (

Bleeker Bleeker is a Dutch occupational surname. Bleeker is an old spelling of ''(linnen)bleker'' ("linen bleacher").Filimanus ''Filimanus'' is a genus of marine ray-finned fishes, threadfins from the family Polynemidae. Features The fishes of the genus ''Filimanus'' have a body which is oblong to moderately deep and compressed. They have a well developed adipose ey ...

'' ** ''

Filimanus heptadactyla ''Filimanus'' is a genus of marine ray-finned fishes, threadfins from the Family (biology), family Polynemidae. Features The fishes of the genus ''Filimanus'' have a body which is oblong to moderately deep and compressed. They have a well develo ...

'' (

Cuvier Jean Léopold Nicolas Frédéric, Baron Cuvier (; 23 August 1769 – 13 May 1832), known as Georges Cuvier, was a French naturalist and zoologist, sometimes referred to as the "founding father of paleontology". Cuvier was a major figure in nat ...

, 1829) (Sevenfinger threadfin) ** ''

Filimanus hexanema ''Filimanus'' is a genus of marine ray-finned fishes, threadfins from the family Polynemidae. Features The fishes of the genus ''Filimanus'' have a body which is oblong to moderately deep and compressed. They have a well developed adipose eyelid ...

'' (Cuvier 1829) (Javanese threadfin) ** ''

Filimanus perplexa ''Filimanus'' is a genus of marine ray-finned fishes, threadfins from the family Polynemidae. Features The fishes of the genus ''Filimanus'' have a body which is oblong to moderately deep and compressed. They have a well developed adipose ey ...

'' Feltes 1991 (Splendid threadfin) ** ''

Filimanus sealei ''Filimanus'' is a genus of marine ray-finned fishes, threadfins from the family Polynemidae. Features The fishes of the genus ''Filimanus'' have a body which is oblong to moderately deep and compressed. They have a well developed adipose ey ...

'' ( Jordan &

Richardson Richardson may refer to: People * Richardson (surname), an English and Scottish surname * Richardson Gang, a London crime gang in the 1960s * Richardson Dilworth, Mayor of Philadelphia (1956-1962) Places Australia * Richardson, Australian Cap ...

, 1910) (Eightfinger threadfin) ** ''

Filimanus similis ''Filimanus'' is a genus of marine ray-finned fishes, threadfins from the Family (biology), family Polynemidae. Features The fishes of the genus ''Filimanus'' have a body which is oblong to moderately deep and compressed. They have a well develo ...

'' Feltes 1991 (Indian sevenfinger threadfin) ** ''

Filimanus xanthonema ''Filimanus'' is a genus of marine ray-finned fishes, threadfins from the family Polynemidae. Features The fishes of the genus ''Filimanus'' have a body which is oblong to moderately deep and compressed. They have a well developed adipose eyelid ...

'' ( Valenciennes, 1831) (Yellowthread threadfin) * Genus '' Galeoides'' ** '' Galeoides decadactylus'' (

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 ...

, 1795) ( Lesser African threadfin) * Genus ''

Leptomelanosoma The Indian threadfin (''Leptomelanosoma indicum'') is a species of marine ray-finned fish from the family Polynemidae, the threadfins. It is a coastal species from south-east Asia which has been recorded in Papua New Guinea. Description The Indi ...

'' ** ''

Leptomelanosoma indicum The Indian threadfin (''Leptomelanosoma indicum'') is a species of marine ray-finned fish from the family Polynemidae, the threadfins. It is a coastal species from south-east Asia which has been recorded in Papua New Guinea. Description The Indi ...

'' (Shaw, 1804) (

Indian threadfin The Indian threadfin (''Leptomelanosoma indicum'') is a species of marine ray-finned fish from the Family (biology), family Polynemidae, the threadfins. It is a coastal species from south-east Asia which has been recorded in Papua New Guinea. De ...

) * Genus '' Parapolynemus'' ** '' Parapolynemus verekeri'' ( Saville-Kent, 1889) ( Dwarf paradise fish) * Genus '' Pentanemus'' ** ''

'' ( Linnaeus,

1758 Events January–March * January 1 – Swedish biologist Carl Linnaeus (Carl von Linné) publishes in Stockholm the first volume (''Animalia'') of the 10th edition of Systema Naturae, 10th edition of ''Systema Naturae'', the sta ...

) ( Royal threadfin) * Genus '' Polydactylus'' (likely not monophyletic) ** '' Polydactylus approximans'' (

Lay Lay may refer to: Places *Lay Range, a subrange of mountains in British Columbia, Canada *Lay, Loire, a French commune *Lay (river), France *Lay, Iran, a village *Lay, Kansas, United States, an unincorporated community People * Lay (surname) * ...

Bennett Bennett may refer to: People *Bennett (name), including a list of people with the surname and given name Places Canada * Bennett, Alberta *Bennett, British Columbia * Bennett Lake, in the British Columbia and Yukon Territory **Bennett Range **Benn ...

, 1839) (Blue bobo) ** '' Polydactylus bifurcus'' Motomura, Kimura & Iwatsuki, 2001 (Slender fivefinger threadfin) ** '' Polydactylus longipes'' Motomura, Okamoto & Iwatsuki, 2001 (Long-limb threadfin) ** '' Polydactylus luparensis'' Lim, Motomura & Gambang, 2010 (Sarawak giant threadfin) ** ''

Polydactylus macrochir The king threadfin (''Polydactylus macrochir''), also known as the blind salmon, blink tassel-fish, burnett salmon, gold threadfin, king salmon, kingfish, Sheridan threadfin, triped tassel fish, or threadfin salmon, is a species of marine ray-fin ...

'' ( Günther, 1867) (

King threadfin The king threadfin (''Polydactylus macrochir''), also known as the blind salmon, blink tassel-fish, burnett salmon, gold threadfin, king salmon, kingfish, Sheridan threadfin, triped tassel fish, or threadfin salmon, is a species of marine ray-fin ...

) ** '' Polydactylus macrophthalmus'' (

Bleeker Bleeker is a Dutch occupational surname. Bleeker is an old spelling of ''(linnen)bleker'' ("linen bleacher").Polydactylus malagasyensis'' Motomura & Iwatsuki, 2001 (African blackspot threadfin) ** '' Polydactylus microstomus'' (

Bleeker Bleeker is a Dutch occupational surname. Bleeker is an old spelling of ''(linnen)bleker'' ("linen bleacher").Polydactylus mullani'' (Hora, 1926) (Arabian blackspot threadfin) ** '' Polydactylus multiradiatus'' ( Günther, 1860) (Australian threadfin) ** '' Polydactylus nigripinnis'' Munro, 1964 (Blackfin threadfin) ** '' Polydactylus octonemus'' ( Girard, 1858) (Atlantic threadfin) ** '' Polydactylus oligodon'' ( Günther, 1860) (Littlescale threadfin) ** ''

Polydactylus opercularis ''Polydactylus'' is a genus of threadfin that mainly are native to the Indian, Atlantic and Pacific Oceans, especially in coastal or brackish waters (such as mangrove or estuaries). Some may even enter rivers and a single, ''P. macrophthalmus'', ...

'' Seale &

Bean A bean is the seed of several plants in the family Fabaceae, which are used as vegetables for human or animal food. They can be cooked in many different ways, including boiling, frying, and baking, and are used in many traditional dishes th ...

, 1907 (Yellow bobo) ** '' Polydactylus persicus'' Motomura & Iwatsuki, 2001 (Persian blackspot threadfin) ** '' Polydactylus plebeius'' (

Broussonet Pierre Marie Auguste Broussonet (28 February 1761 – 17 January 1807) was a French naturalist who contributed primarily to botany. He was born in Montpellier, where he was educated, and travelled to Morocco, Spain, the Canary Islands, and Souther ...

, 1782) (Striped threadfin) ** ''

Polydactylus quadrifilis The giant African threadfin (''Polydactylus quadrifilis'') is a species of ray-finned fish from the threadfin family Polynemidae. It is found in the eastern Atlantic Ocean off the west coast of Africa. Description The giant African threadfin is, ...

'' (

, 1829) (Giant African threadfin) ** ''

Polydactylus sexfilis ''Polydactylus sexfilis'', the six-finger threadfin or yellowthread threadfin, is a species of marine ray-finned fish, a threadfin from the family Polynemidae which is found in the Indian and Pacific Oceans. Description ''Polydactylus sexfilis'' ...

'' ( Valenciennes, 1831) (Sixfinger threadfin) ** ''

Polydactylus sextarius ''Polydactylus sextarius'', the blackspot threadfin, is a species of marine ray-finned fish, a threadfin from the family Polynemidae which is native to the western Pacific and eastern Indian Oceans. Distribution ''Polydactylus sextarius'' is ...

'' (

Schneider Schneider may refer to: Hospital * Schneider Children's Medical Center of Israel People * Schneider (surname) Companies and organizations * G. Schneider & Sohn, a Bavarian brewery company * Schneider Rundfunkwerke AG, the former owner of th ...

, 1801) (Blackspot threadfin) ** ''

Polydactylus siamensis ''Polydactylus'' is a genus of threadfin that mainly are native to the Indian, Atlantic and Pacific Oceans, especially in coastal or brackish waters (such as mangrove or estuaries). Some may even enter rivers and a single, ''P. macrophthalmus'', ...

'' Motomura, Iwatsuki & Yoshino, 2001 (Largemouth striped threadfin) ** '' Polydactylus virginicus'' ( Linnaeus,

) (Barbu) * Genus '' Polynemus'' ** ''

Polynemus aquilonaris ''Polynemus aquilonaris'', commonly known as the northern paradise fish, is a fish of the threadfin family Polynemidae. It is native to the large rivers of mainland Southeast Asia. Description ''Polynemus aquilonaris'' is a medium-sized species ...

'' Motomura, 2003 (

Northern paradise fish ''Polynemus aquilonaris'', commonly known as the northern paradise fish, is a fish of the threadfin family Polynemidae. It is native to the large rivers of mainland Southeast Asia. Description ''Polynemus aquilonaris'' is a medium-sized species ...

) ** '' Polynemus bidentatus'' Motomura & Tsukawaki, 2006 ** ''

Polynemus dubius ''Polynemus'' is a genus of threadfins (family Polynemidae). They are native to South and Southeast Asia and, depending on the species, occur in freshwater, brackish, and/or marine environments. The family Polynemidae is characterized by the pec ...

Bleeker Bleeker is a Dutch occupational surname. Bleeker is an old spelling of ''(linnen)bleker'' ("linen bleacher").Eastern paradise fish Eastern may refer to: Transportation *China Eastern Airlines, a current Chinese airline based in Shanghai *Eastern Air, former name of Zambia Skyways *Eastern Air Lines, a defunct American airline that operated from 1926 to 1991 *Eastern Air Li ...

) ** ''

Polynemus hornadayi ''Polynemus'' is a genus of threadfins (family Polynemidae). They are native to South and Southeast Asia and, depending on the species, occur in freshwater, brackish, and/or marine environments. The family Polynemidae is characterized by the pec ...

'' Myers, 1936 ( Hornaday's paradise fish) ** '' Polynemus kapuasensis'' Motomura & van Oijen, 2003 (

Kapuas elegant paradise fish Kapuas may refer to: * Kapuas River * Kapuas Hulu, in West Borneo * Kapuas Regency, in Central Borneo * Kapuas River (Barito River) The Kapuas River (or Kapueas) is a river in the Indonesian part of Borneo island. It originates in the Müller ...

) ** '' Polynemus melanochir'' Valenciennes, 1831 (

Blackhand paradise fish Black Hand or The Black Hand may refer to: Extortionists and underground groups * Black Hand (anarchism) (''La Mano Negra''), a presumed secret, anarchist organization based in the Andalusian region of Spain during the early 1880s * Black Hand (e ...

) ** ''

Polynemus multifilis ''Polynemus multifilis'', the elegant paradise fish is a species of ray-finned fish, a threadfin from the Family (biology), family Polynemidae which is found in rivers in southeast Asia. Description ''Polynemus multifilis'' is a medium-sized spe ...

'' Temminck & Schlegel, 1843 (

Elegant paradise fish ''Polynemus multifilis'', the elegant paradise fish is a species of ray-finned fish, a threadfin from the family Polynemidae which is found in rivers in southeast Asia. Description ''Polynemus multifilis'' is a medium-sized species of threadfin ...

) ** ''

Polynemus paradiseus The paradise threadfin (''Polynemus paradiseus'') is a species of catadromous ray-finned fish, a threadfin from the family Polynemidae which is found in south and southeast Asia in freshwater rivers where it is a valued food fish. Description T ...

'' Linnaeus,

( Paradise threadfin)

Timeline of genera

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 from: -55.8 till: -33.9 color:eocene text: Eocene from: -33.9 till: -23.03 color:oligocene text:

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

from: -23.03 till: -5.332 color:miocene text: Miocene 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 The Paleogene ( ; British English, also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period, geologic period and system that spans 43 million years from the end of the Cretaceous Period million yea ...

from: -23.03 till: -2.588 color:neogene text:

Neogene The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...

from: -2.588 till: 0 color:quaternary text: Q. PlotData= align:left fontsize:M mark:(line,white) width:5 anchor:till align:left color:miocene bar:NAM1 from: -23.03 till: 0 text: Pentanemus color:miocene bar:NAM2 from: -11.608 till: 0 text: Polydactylus PlotData= align:center textcolor:black fontsize:M mark:(line,black) width:25 bar:period from: -65.5 till: -55.8 color:paleocene text: Paleocene from: -55.8 till: -33.9 color:eocene text: Eocene from: -33.9 till: -23.03 color:oligocene text:

from: -23.03 till: -2.588 color:neogene text:

from: -2.588 till: 0 color:quaternary text: Q.

References

* *

External links

Fisheries Western Australia - Threadfins Fact SheetThe Paradise threadfin, Polynemus paradiseus
{{Taxonbar, from=Q924957 Fish of Hawaii Taxa named by Constantine Samuel Rafinesque id:Senangin