| Atlantic threadfin | |
|---|---|
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Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Carangiformes |
| Family: | Polynemidae |
| Genus: | Polydactylus |
| Species: | P. octonemus |
| Binomial name | |
| Polydactylus octonemus (Girard, 1858) | |
| Synonyms [2] | |
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The Atlantic threadfin (Polydactylus octonemus) is a species of ray-finned fish, a threadfin from the family Polynemidae native to subtropical and temperate waters of the western Atlantic Ocean and the Gulf of Mexico.
The Atlantic threadfin is a medium-sized species of threadfin which grows to a maximum total length of 30 centimetres (12 in), although most fish have a total length of around 25 centimetres (9.8 in). [2] It has a pointed snout and an almost straight dorsal profile on its head. [3]
There are two separate dorsal fins; the first dorsal fin contains eight spines whose bases are of similar thickness, and the second dorsal fin has a single spine and 11 to 13 soft rays. The anal fin has three spines and 12 to 14 soft rays. The base of the anal fin is longer than that of the second dorsal fin. The pectoral fin has 14 to 16 unbranched rays and has a length equivalent to 24 to 29% of the standard length. Its tip does not reach the tip of the pelvic fins. There are eight pectoral filaments, sometimes nine, and the first pectoral filament is the shortest, extending beyond the level of the front of the pelvic fins while the second to fifth pectoral filaments reach slightly farther and the sixth filament may extend slightly beyond the tip of the pelvic fins. The seventh pectoral filament does not extend as far as the anal-fin origin. The eighth pectoral filament is the longest and it has a length equivalent to 39 to 51% of the standard length. The filaments tend to be longer in adults than they are in young fish. The caudal fin is deeply forked with its upper and lower caudal-fin lobes not bearing filaments. There are 56 to 64 pored scales in the lateral line which is forked on the caudal fin, with branches reaching onto the rear margin of the lobes of the tail. [3]
The upper sides of the head and the flanks are tinged with a slight darkish silver shade, lightening on the lower flanks. It has a semi-translucent snout. The first and second dorsal fins are coloured dusky yellow; the pectoral fin is black while the pectoral filaments are translucent. The dusk-yellow anal fin has a white rear margin. The caudal fin is dusky yellowish with a black rear margin. [3]
The Atlantic threadfin is found in the western Atlantic where it occurs from New Smyrna Beach in Florida south and west into the Gulf of Mexico coast of the United States to the Yucatan Peninsula in Mexico. It is absent from the northern part of the Yucatan Peninsula and from Cuba. Vagrants stray as far north as Long Island. [1]
The Atlantic threadfin occurs over sandy or muddy bottoms and on beaches, commonly being observed in the surf zone. It occurs at depths between 5 and 66 metres (16 and 217 ft) in the Gulf of Mexico but peak numbers are found at depths of 5 to 16 metres (16 to 52 ft). Young specimens, of lengths less than 66 millimetres (2.6 in) have been taken from the surface of the Gulf of Mexico where the sea was 1,035 to 2,736 metres (3,396 to 8,976 ft). Sexual maturity is reached at total lengths between 165 and 210 millimetres (6.5 and 8.3 in), when they are around 7 to 9 months of age. Spawning probably occurs in the Gulf of Mexico, off Louisiana and Texas and mainly takes place between mid-December and mid-March and lasts between 45 and 120 days overall. The 2–4 month old larvae live in waters shallower than 16 metres (52 ft), dispersing towards deeper waters in the early summer. They typically live no longer then 1 year but may be longer in fish that survive their first pelagic spawning. [3]
The Atlantic threadfin was originally formally described as Polynemus octonemus in 1858 by Charles Frédéric Girard with the type locality of Brazos Santiago, and Galveston, Texas. [4]
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 gag grouper, also known as velvet rockfish, the gag, or charcoal belly, 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 comes from warmer parts of the West Atlantic, including the Caribbean and Gulf of Mexico. It is a drab, mottled-gray fish lacking the distinguishing features of most other groupers. Its pattern of markings resemble the box-shaped spots of the black grouper. It lacks the streamer-points on the tail fin that scamp and yellowmouth grouper have and lacks yellow coloration around the mouth.
Eleutheronema tetradactylum, the fourfinger threadfin, known as ranwas in India is a species of marine ray-finned fish, a threadfin from the family Polynemidae which occurs in the Indian and western Pacific Ocean.
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.
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, striped 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.
Nemipterus bipunctatus, the Delagoa threadfin bream, Bleeker's threadfin bream or butterfly bream, is a species of marine ray-finned fish belonging to the family Nemipteridae, the threadfin and whiptail breams. This demersal fish is found over soft bottoms in the Indian Ocean.
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.
Nemipterus japonicus, the Japanese threadfin bream, is a species of marine ray-finned fish belonging to the family Nemipteridae, the threadfin and whiptail breams. This species is found in the Indo Pacific region and is an important food fish.
The yellowbelly threadfin bream is a species of marine ray-finned fish belonging to the family Nemipteridae, the threadfin and whiptail breams. This fish is found in the western Pacific Ocean.
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.
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 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.
The doublewhip threadfin bream is a species of marine ray-finned fish belonging to the family Nemipteridae, the threadfin breams. This species is found in the Indo-West Pacific region.
