King threadfin

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King threadfin
Polydactylus macrochir.png
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Polynemidae
Genus: Polydactylus
Species:
P. macrochir
Binomial name
Polydactylus macrochir
(Günther, 1867)
Synonyms [1]
  • Polynemus macrochirGünther, 1867
  • Polynemus sheridani Macleay, 1884
  • Polydactylus sheridani(Macleay, 1884)

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-finned fish, a threadfin from the family Polynemidae which is found in southern New Guinea and northern Australia.

Contents

Description

The king threadfin is a large threadfin which can attain a maximum total length of 170 centimetres (67 in) and a maximum published weight of 45 kilograms (99 lb), although the more common total length is 48 centimetres (19 in). [1] It has a pointed snout and the dorsal profile of the head is almost flat in young fish and concave in adults. There are two separate dorsal fins, the first dorsal fin has 8 spines and the second spine is thicker than others. The second dorsal fin has a single spine and 11 to 13 soft rays. The anal fin has 3 spines and 10 to 12 soft rays, the base of the anal fin base is roughly equal in length to the base of the second dorsal fin base. The pectoral fin has 14 or 15 unbranched rays, and has a length equivalent to roughly a quarter of the standard length with its tip just falling short or just reaching the tip of the pelvic fin. There are 5 pectoral filaments with first filament being the shortest, reaching past the level of origin of the pelvic fin. The second pectoral filament extends to past the tip of the pelvic fin. The third and fifth pectoral filaments extend past the level of the origin of the anal fin. The fourth pectoral filament is the longest, having a length equivalent to 40 to 53% of the standard length and this filament extends far beyond the level of the origin of the anal fin. The caudal fin is deeply forked with neither of its lobes being filamentous. There are 60-76 pored scales on its lateral line which is simple In form and extends from the upper end of the gill slit to the upper end of lower caudal fin lobe. The ppper sides of head and the flanks are tinged golden silver, becoming silvery on the lower flanks. Both dorsal fins are pale brown, the pectoral and pelvic fins are vivid yellow. The front portion of the anal fin is yellow, the remainder being yellowish white. The pectoral filaments are white or yellowish white. The tail is greyish with a greyish black rear margin. [2]

Distribution

The king threadfin is found in the eastern Indian Ocean and the western Pacific Ocean. It is found in southern New Guinea and northern Australia. [1] In Australia its range extends from Eighty Mile Beach in Western Australia to the Brisbane River in Queensland. [3] In New Guinea its range extends along the southern coast from Western New Guinea, Indonesia, to the Gulf of Papua in Papua New Guinea. [2]

Habitat and biology

King threadfin occur in shallow, turbid waters such as coastal waters, estuaries, mangrove creeks, and mangrove-lined rivers, over sandbanks and mud substrates. It normally aggregates into loose schools, however, the larger individuals are more frequently recorded as pairs or as individuals. This is a carnivorous species which feeds on prawns and fish. It is a protandrous hermaphrodite and fish between fork lengths of 70 and 100 centimetres (28 and 39 in) appear to be transitional hermaphrodites in that they have mature male and immature female reproductive organs, and they function reproductively as males. King threadfins in the process of transitioning are most frequently recorded from June to September. [1] The females spawn pelagic eggs but little is known about the larvae [3] although the nursery areas are inshore, shallow and of low salinity. [1]

Fisheries

The king threadfin is one of the most important species in the fisheries in the Northern Territory, Queensland and Western Australia and it is caught mostly using coastal set gillnets, and also using fixed tidal traps, beach seines, ring nets and handlines. The fishery in the southern part of the Gulf of Carpentaria is dominated by males in the age range 3-6 years old. In the Gulf of Carpentaria between 1980 and 1987 the gillnet fishery landings of this species equalled an average 30% by weight of total landings. [2] It is a popular sport fishing quarry too and in Queensland and Western Australia there are minimum sizes which can be taken and a bag limit. [4] [5]

Species description

Polydactylus macrochir was first formally described as Polynemus macrochir in 1867 by Albert Günther who gave the type locality as New South Wales, thought to be an error for Queensland. [6]

Related Research Articles

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<i>Eleutheronema tetradactylum</i> Species of fish

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Duskyshoulder trevally Species of fish

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Giant African threadfin Species of fish

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<i>Polydactylus sexfilis</i> Species of fish

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.

False scorpionfish Species of fish

The false scorpionfish, also known as prettyfins, is a species of perciform fish, the only species in genus Centrogenys, which in turn is the only genus in the family Centrogenyidae. They are pale grey or brown and usually grow no longer than 25 cm (9.8 in). False scorpionfish are distributed throughout the Indo-West Pacific, bounded by the Ryukyu Islands of Japan to the north and Australia to the south, the Nicobar Islands to the west and New Guinea to the east.

Longfin grouper Species of fish

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.

Indian threadfin Species of fish

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<i>Polynemus multifilis</i> Species of fish

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<i>Polydactylus sextarius</i> Species of fish

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<i>Polydactylus plebeius</i> Species of fish

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.

Paradise threadfin Species of fish

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.

<i>Filimanus</i> Genus of fishes

Filimanus is a genus of marine ray-finned fishes, threadfins from the family Polynemidae.

Lesser African threadfin Species of fish

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.

Royal threadfin Species of fish

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.

References

  1. 1 2 3 4 5 Froese, Rainer and Pauly, Daniel, eds. (2019). "Polydactylus macrochir" in FishBase. December 2019 version.
  2. 1 2 3 Hiroyuki Motomura & Food and Agriculture Organization of the United Nations (2004). Threadfins of the World (family Polynemidae): An Annotated and Illustrated Catalogue of Polynemid Species Known to Date (PDF). FAO species identification field guide for fishery purposes. 3. Food & Agriculture Org.
  3. 1 2 Dianne J Bray. "Polydactylus macrochir". Fishes of Australia. Museums Victoria. Retrieved 17 Apr 2020.
  4. "King threadfin". Queensland Government. Retrieved 17 April 2020.
  5. "Threadfins" (PDF). Western Australia Government. Retrieved 17 April 2020.
  6. Eschmeyer, William N.; Fricke, Ron & van der Laan, Richard (eds.). "Polynemus macrochir". Catalog of Fishes . California Academy of Sciences . Retrieved 17 April 2020.