| Lesser African threadfin | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Perciformes |
| Family: | Polynemidae |
| Genus: | Galeoides |
| Species: | G. decadactylus |
| Binomial name | |
| Galeoides decadactylus (Bloch, 1795) | |
| Synonyms [2] | |
The lesser African threadfin (Galeoides decadactylus) 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 lesser African threadfin has a rather compress, moderately elongated body with has a depth which is around one thirds of the standard length. The mouth has an inferior position and is overhung by the blunt snout. The jaws extend past the eye. It has two dorsal fins which are widely separated, the first dorsal fin has 8 weak spines and the second has a single spine and 13 or 14 soft rays while the anal fin has 3 spines and 11 or 12 soft rays. The second dorsal fin and anal fin have bases which are approximately equal in length. The pectoral fins are positioned low on the body, this fin has 9 or 10 detached threadlike lower rays. It has a count scales in the lateral line of 45–46. This species is a dull silvery colour, with a brownish to green tint in the back fading to whitish on the breast and belly. There is a large, round, dusky blotch directly below the first dorsal fin which sits beneath the lateral line at level of first dorsal fin, this blotch is similar in size to the eye. [3] The lesser African threadfin can attain a total length of 50 centimetres (20 in) but 30 centimetres (12 in) is more normal. [2]
The lesser African threadfin is found in the eastern Atlantic Ocean from Morocco south as far as Angola. It is also found around the Canary Islands and Cape Verde Islands and has been recorded off Namibia and in the Mediterranean Sea off Algeria. [4] [1]
The lesser African threadfin occurs over muddy bottoms in shallow coastal waters at depths between 10 and 70 metres (33 and 230 ft), and they are often observed in estuaries and lagoons. Its diet is dominated by crustaceans but it will feed on small fishes. The stomach contents of specimens taken from the open sea had almost no detritus while those taken in estuaries had 31% of their stomach contents made up of detritus In a study near Lagos in Nigeria it was found that 25% of the females present had developed from the juvenile stage, i.e. had not been males, while the remainder had passed through a hermaphroditic phase having been males. Hermaphroditic fish are not reproductively functional. The sex composition of that population was 63.73% male, 22.22% hermaphroditic and 14.3% female. Spawning occurs throughout the year but peaks in the dry season and almost ceasesd during the rains. Most of these fish will not survive past the age of four years old. [4]
The lesser African threadfin is an important quarry species in the commercial trawl fishery of the eastern Atlantic, and it makes up between 10 and 20% of the total landings by weight. In 2000-2006 the annual catch from western Africa averaged 15,600 tonnes, with the largest catches being landed in Nigeria, Ghana, and Gabon. In Senegal, it is regarded as an important coastal resource. Fishermen use beach seines, gillnets and shallow haul nets to catch this species. This species is highly regarded and is marketed fresh, dried salted or smoked. [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 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.
The white grouper 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. The white grouper is found in the subtropical eastern Atlantic Ocean and the southern Mediterranean Sea.
The yellowfin grouper 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 warmer waters of the western Atlantic Ocean.
Epinephelus andersoni, the catface grouper, brown-spotted grouper, catface rockcod or brown spotted rockcod, 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 southwestern Indian Ocean where it is associated with reefs.
The orange-spotted grouper, also known as the brown-spotted rockcod, estuary cod, estuary rockcod, goldspotted rockcod, greasy cod, North-west groper, orange spotted cod or blue-and-yellow grouper, 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 has an Indo-Pacific distribution and is found in marine and brackish waters.
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 European flounder is a flatfish of European coastal waters from the White Sea in the north to the Mediterranean and the Black Sea in the south. It has been introduced into the United States and Canada accidentally through transport in ballast water. It is caught and used for human consumption.
Cephalopholis taeniops, the African hind, bluespotted sea bass or spotted grouper, is a species of marine ray-finned fish, a grouper from the subfamily Epinephelinae which is in the family Serranidae which also includes the anthias and sea basses. This species occasionally makes its way into the aquarium trade and is a target for local fisheries. It is found in the eastern Atlantic 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, 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 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.
