| Polydactylus sexfilis | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Perciformes |
| Family: | Polynemidae |
| Genus: | Polydactylus |
| Species: | P. sexfilis |
| Binomial name | |
| Polydactylus sexfilis (Valenciennes, 1831) | |
| Synonyms [1] | |
| |
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.
Polydactylus sexfilis is a medium-sized species, which attains a maximum total length of 61 centimetres (24 in) and a weight of 3.2 kilograms (7.1 lb). [1] It has a pointed snout and the head has an almost horizontal profile. There are two separated dorsal fins, the first dorsal fin has 8 spines and the second dorsal fin contains a single spine and 12 or 13 soft rays. The anal fin has 3 spines and 11 or 12 soft rays, the base of the anal fin is roughly equal in length to the second dorsal-fin base. The pectoral fin has 15 or 16 rays, and this fin has a length which is equal to 20 to 23% of the standard length, and its tip does not reach the tip of pelvic fin; almost all the rays of the pectoral fin are unbranched except that in the largest specimens some of the rays may be branched. There are six pectoral filaments, the first is the shortest and does not reachthe pelvic fin origin. The second to fifth filaments reach past the pelvic-fin origin and the sixth is the longest and reached to or just beyond the tip f the pelvic fin. The caudal fin is deeply forked and its lobes are non-filamentous, although they are long. The simple lateral line has 60 to 67 pored scalesand runs from the upper end of the gill slit to the upper end of the lower lobe of the caudal fin. The head and flanks are tinged silvery brown dorsally, becoming silvery on their lower flanks. There are 7 to 9 prominent dark longitudinal stripes above the lateral line and 1 to 12 faint stripes below it, these may be absent in smaller fish. The first dorsal fin is black; the second dorsal fin is greyish with the last ray being white. The base of the pectoral fin is greyish black, darkening to black towards the rear. The pectoral filaments are greyish-black with white tips and bases. The front part of the pelvic fin is greyish black with the rest of it being coloured white. The anal fin is greyish-black with its last ray being white. The tail is uniformly greyish black. [2]
Polydactylus sexfilis has an Indo-Pacific distribution. It tends to occur mainly around oceanic islands. It has been recorded from Mauritius, Seychelles, Kenya and a number of other islands in the northern Indian Ocean. It is also found from Indonesia north to the island groups of southern Japan and east to the Hawaiian Islands, French Polynesia and Pitcairn Island. [1] It has not been collected from continental Australia but has occurred from Cocos (Keeling) Island. [3]
Polydactylus sexfilis is found in shallow water which are less than 50 metres (160 ft) along sandy and rocky coastal beaches, in lagoons and near reef areas near oceanic islands, often where the water is very turbulent. It feeds largely on crustaceans and fishes. They reach sexual maturity as males when they attain a fork length of 20–25 centimetres (7.9–9.8 in) and then changing sex to fertile females after an intermediate hermaphrodite stage when they reach a fork length of 30–40 centimetres (12–16 in). Spawning is governed by the phases of the moon. [2]
Polydactylus sexfilis is an important species for commercial fisheries in Hawaii where it is also used in aquaculture. [2] In Hawaiian this species is called moi and in pre colonial Hawaii the moi was reserved for royalty. They were farmed in specially created ponds. [4]
Polydactylus sexfilis was first formally described in 1831 by Achille Valenciennes as Polynemus sexfilis with the type locality given as Mauritius. [5]
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.
This glossary of ichthyology is a list of definitions of terms and concepts used in ichthyology, the study of fishes.
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.
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.
Plectorhinchus albovittatus, the two-striped sweetlips or giant sweetlips, is a species of marine ray-finned fish, a sweetlips belonging to the subfamily Plectorhinchinae, part of the grunt family Haemulidae. It is native to the Indian Ocean and the western Pacific Ocean.
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.
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.
Clinus agilis, the agile klipfish, is a species of clinid found in subtropical waters of the Atlantic Ocean from Namibia to South Africa where it is commonly found in estuaries and tide pools. This species can reach a maximum length of 10 centimetres (3.9 in).
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.
Pomacentrus chrysurus, the whitetail damselfish, is a species of damselfish in the family Pomacentridae. It is found in the Indo-Pacific. It can grow up to 9 centimetres (3.5 in). They are found at a depth range from 0 to 3 metres.
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.
Nemipterus randalli, or Randall's threadfin bream, is a species of ray-finned fish from the family Nemipteridae, the threadfin breams, which is native to the western Indian Ocean and the Red Sea, it has invaded the eastern Mediterranean by Lessepsian migration through the Suez Canal.
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.