| Royal threadfin | |
|---|---|
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Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Perciformes |
| Family: | Polynemidae |
| Genus: | Pentanemus |
| Species: | P. quinquarus |
| Binomial name | |
| Pentanemus quinquarus (Linnaeus, 1758 | |
| Synonyms [2] | |
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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.
The royal threadfin is a medium-sized threadfin species reaching a maximum total length of 35 centimetres (14 in), although a more normal length is 25 centimetres (9.8 in). [2] It has two separate dorsal fins, the first dorsal fin has 8 spines and the second dorsal fin has a single spine and 14 or 15 soft rays. The anal fin contains 3 spines and 24 to 30 soft rays, with a base which is longer than that of the second dorsal-fin. The pectoral fin has 14 to 16 unbranched rays and is 30% to 42% of the fish's standard length with its tip extending to or just short of the centre of the base of the anal fin. The pectoral fin is situated far below the midline of body. There are 5 pectoral filaments, the first being the shortest and this filament just reaches to or extends beyond the start of the anal fin. The remaining pectoral filaments reach well past the ends of lobes of the caudal fins with the third filament being the longest being 2.5-3 times the standard length. The caudal fin is deeply forked and the lobes are not fialmented, the length of the upper lobe is 36% to 46% of the standard length and lower lobe is 38 %to 47% of the standard length. There are 68-76 pored scales in the simple lateral line which extends from upper end of gill opening to the middle of the caudal fin fork. The upper sides of its head and body tinged with gold, this changes to silver on the lower flanks. The margins of both dorsal fins and the caudal fins are black, the rest of these fins are blackish while pelvic and anal fins are white. The pectoral fin is yellow with melanophores. The base of pectoral filaments is white, darkening towards their tips. [3]
The royal threadfin is found in the eastern Atlantic Ocean where it occurs along the western coast of Africa from Senegal to Angola. [3] It has been recorded from Cape Verde and Mauritania. [2] A record from Cuba of a half grown fish from the mid-nineteenth century remains the only record from the western Atlantic Ocean. [3]
The royal threadfin occurs over muddy substrates in shallow coastal waters between 10 and 70 metres (33 and 230 ft) in depth. It is also often recorded in estuaries and lagoons. It is a carnivorous fish and its diet consists of crustaceans and small fish. Spawning takes place off Lagos throughout the year but peaks in the dry season and nearly stops altogether during the rainy season. Unlike other threadfins this species has a small proportion of the population which are hermaphroditic. It is also relatively short lived and few fish survive beyond 2 years of age. [3]
The royal threadfin is mainly taken as by-catch off Lagos by shrimp beam trawlers, but it is still commercially important. Most of the fish caught are subadults and this pattern is likely replicated throughout West Africa where it is one of the most important commercial species in this region> It is caught using trawls, but also by gillnet and beach seine. In Senegal, it is regarded as less valuable due to its smaller size and lower abundance than the lesser African threadfin. [1]
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.
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.
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.
Synodontis grandiops is a species of upside-down catfish endemic to the Democratic Republic of the Congo, Burundi, and Tanzania, where it is only known from Lake Tanganyika. It was first described by Jeremy John Wright and Lawrence M. Page in 2006, from specimens collected at multiple points along the shore of Lake Tanganyika. The species name is a Latinized combination of the Latin "grandi", meaning large or big, and the Greek "ops", meaning eye, a reference to the relatively large eyes of this fish.
Synodontis ilebrevis is a species of upside-down catfish endemic to Zambia, where it is only known from Lake Tanganyika. It was first described by Jeremy John Wright and Lawrence M. Page in 2006, from specimens collected from Lake Tanganyika at Cape Chaitika, Zambia. The species name comes from the Latin word "ile", meaning intestine, and the Latin word "bevis", meaning short, and refers to the relatively short gut of this species.
Synodontis sorex is a species of upside-down catfish that is widely distributed in the rivers of northern Africa. It was first described by German zoologist Albert Günther in 1864, from specimens obtained in the upper Nile River, near Khartoum, Sudan. The species name sorex comes from the Latin word for shrew or shrew-mouse, the allusion was not explained. It possibly describes the pointed snout or the long, slender teeth.
Synodontis lucipinnis is a species of upside-down catfish endemic to Zambia, where it is only known from the Musende Rocks area (Mpulungu) of Lake Tanganyika. It was first described by Jeremy John Wright and Lawrence M. Page in 2006. The species name "lucipinnis" is derived from a combination of the Latin luci, meaning bright or clear, and the Latin pinnis, meaning fin. This refers to the light coloration in a patch on the base of the fins of this species.
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 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.
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, 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.
