Eleutheronema tetradactylum | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Perciformes |
Family: | Polynemidae |
Genus: | Eleutheronema |
Species: | E. tetradactylum |
Binomial name | |
Eleutheronema tetradactylum (Shaw, 1804) | |
Synonyms [2] | |
Eleutheronema tetradactylum, the fourfinger threadfin, known as ranwas in Pakistan, is a species of marine ray-finned fish, a threadfin from the family Polynemidae which occurs in the Indian and western Pacific Ocean.
Eleutheronema tetradactylum has two dorsal fins; the first has 9 spines and the second has 13–15 soft rays, with 13 being the mean. The anal fin has 3 spines and 14–19 soft rays. The pectoral fins have 16–18 rays, and there are 4 pectoral filaments. The upper sides of the head and body have a slight darkish silver tinge, lighting in the lower flanks. Both dorsal fins show a blackish anterior margin, with the remaining parts of the fins translucent and slightly dusky. The membranes of the pectoral fins are vivid yellow in smaller individuals, but in larger fish this becomes duskier. The pectoral filaments are white. The pelvic fins are white with a yellow front edge, while the caudal fin is blackish with a yellowish base. This species can attain a maximum total length of 2 metres (6.6 ft), although 50 centimetres (20 in) is a more normal size. [2]
Eleutheronema tetradactylum has an Indo-Pacific distribution and ranges from the Persian Gulf to Australia and Papua New Guinea. [2]
Eleutheronema tetradactylum adults show a preference for shallow muddy substrates in coastal waters and they may enter rivers. The juveniles occur in estuaries. In the winter the adults move up rivers. It is normally observed in loose schools, but larger fish are more often recorded as pairs or individuals. It is a carnivorous species which preys on prawns and fish. The fish preyed upon are mainly grey mullets, anchovies and drums, and they sometimes feed on polychaetes. The ratio of crustaceans to fish fed on varies with the season. The small larvae have a diet dominated by copepods and mysids although they also feed on small decapods while larger juveniles feed prawns and mysids. This species is a protandrous hermaphrodite and Australian studies found that they were males at fork length of 24–47 centimetres (9.4–18.5 in), hermaphrodites at fork lengths between 25–46 centimetres (9.8–18.1 in) FL and females are found at fork lengths of 28–72 centimetres (11–28 in). Off the northeast cost of Queensland, most of the fish with fork lengths greater than 45–50 centimetres (18–20 in) are females. The hermaphroditic fish form once they reach 1- to 2-year-old, and then females begin to appear at 2-3-years old. It is thought that the males change to hermaphrodites just after spawning in April and May and they remain in a hermaphroditic state until the next breeding season is over. They then progress from hermaphrodites to females before the breeding season after that. The larval stage is little known but it is known that lower estuaries, tidal swamps and lagoons, and the shallows along the foreshores are used as nursery areas. [2]
Eleutheronema tetradactylum is marketed fresh, frozen, and dried or salted. [2] This species is also used in aquaculture. [3] This species is one of an important commercial quarry for fisheries in Kuwait and the species is also taken as bycatch. They are one of the more expensive fish in the Kuwaiti and Iranian markets. [4]
Eleutheronema tetradactylum has not had its global conservation status evaluated by the IUCN but it has been classified as Endangered in the Persian Gulf where the population appears to be in a rapid decline. [4]
Eleutheronema tetradactylum is a widespread and commercially important species and, as such, has a number of English common names, other than the fourfinger threadfin. In Australia it is known as the blue threadfin, although other names include blind tassel-fish, blue salmon, bluenose salmon, blunt-nosed salmon, burnett salmon, Colonial salmon, Cooktown salmon, giant threadfin, kingfish, Rockhampton kingfish, Rockhampton salmon, tassel-fish and threadfin. [5] In India names used include Gurjali fish in Bengali, [6] Indian salmon, white salmon, row ball and horse's friend. [2]
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 and about 40 species. An unrelated species sometimes known by the name threadfin, Alectis indicus, is properly the Indian threadfish.
The Atlantic threadfin is a species of ray-finned fish a threadfin from the family Polynemidae which is native to subtropical and temperate waters of the western Atlantic Ocean and the Gulf of Mexico.
Nemipterus virgatus, the golden threadfin bream or yellowlipped threadfin bream, is a species of marine ray-finned fish belonging to the family Nemipteridae, the threadfin breams. This species is found in the Western Pacific Ocean.
Dendrochirus brachypterus, the dwarf lionfish, short-finned turkeyfish, shortspine rockcod or shortspine scorpionfish, is a species of marine ray-finned fish belonging to the family Scorpaenidae, the scorpionfishes and lionfishes. It is found in the Indo-Pacific. It is sometimes found in the aquarium trade.
The giant African threadfin 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.
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.
The king threadfin, 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-finned fish, a threadfin from the family Polynemidae which is found in southern New Guinea and northern Australia.
The longfin grouper, also known as the longfin rockcod, bar-breasted rock-cod, Gilbert's rock-cod, honeycomb rockcod, spotted groper or wirenet cod, is a species of marine ray-finned fish, a grouper from the subfamily Epinephelinae which is part of the family Serranidae, which also includes the anthias and sea basses. It is found in the Western Pacific Ocean.
The Indian threadfin 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.
Menticirrhus saxatilis, the northern kingfish or northern kingcroaker, is a species of marine fish in the family Sciaenidae. It lives in the shallow coastal waters of the western Atlantic Ocean and Gulf of Mexico.
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.
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.
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.
Polydactylus plebeius, the striped threadfin, also known as the common threadfin, Northern threadfin or puttynose, is a species of marine fish native to the Indo-Pacific.
The dwarf paradise fish, 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 and it is found in Australia and New Guinea.
Polynemus is a genus of threadfins. They are native to South and Southeast Asia and, depending on the species, occur in freshwater, brackish, and/or marine environments.
The paradise threadfin 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.
Filimanus is a genus of marine ray-finned fishes, threadfins from the family Polynemidae.
The lesser African threadfin is a species of marine ray-finned fish, a threadfin from the family Polynemidae which is found in the eastern Atlantic Ocean off the western coast of Africa.
The royal threadfin 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.