African brown knifefish | |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Osteoglossiformes |
Family: | Notopteridae |
Subfamily: | Xenomystinae |
Genus: | Xenomystus Günther, 1868 |
Species: | X. nigri |
Binomial name | |
Xenomystus nigri (Günther, 1868) | |
The African brown knifefish (Xenomystus nigri) is the only species in the genus Xenomystus of the family Notopteridae. This fish is found in the Chad, Nile, Congo, Ogowe and Niger basins, as well as coastal river basins in Sierra Leone, Liberia, Togo, Benin and Cameroon. [1]
This fish reaches 30 cm (12 in) in standard length. [1] The body of these fish is unusual; it is ventrolaterally flattened and elongated, giving the appearance of a knife blade. The caudal and anal fins are fused and run from beneath the gill opening to the pointed end of the body, creating a uniform, skirt-like fin. This appendage gives the animal superior control in the water, as it is able to propel itself forward and backward with a minimum of wasted energy. The pelvic fins are extremely reduced and are not used in locomotion. The dorsal fin is absent. The pectoral fins of the African brown knifefish are lengthy and designed to give the animal precise control as it swims. They are often employed in a windmilling motion, in conjunction with the caudal/anal fin, as the fish retreats into its lair.
The scales of the knifefish are extremely small, giving it a smooth appearance broken only by its fairly prominent lateral line. Apart from its eyes, the lateral line is the knifefish's most important sensory apparatus. The African brown knifefish is nocturnal and uses the nerve-filled pits running down its body to navigate lightless waters. In addition, the eyes of this fish are large in relation to its body size. They provide the animal with excellent night vision.
The mouth is large, and the fish also possesses a pair of short barbels used in hunting. The knifefish, when not hiding away, spends much of its time swimming with its head down and the barbels in close proximity to the substrate. Combined with its acute eyes, the barbels aid the fish in locating its food.
This fish inhabits quiet water with vegetation. Females lay 150–200 eggs of 2 mm (0.08 in) in diameter. This species can produce barking sounds. They come to the surface from time to time to swallow air. They feed on worms, crustaceans, insects, and snails. [1]
This species is sometimes available as an aquarium fish, and has been popular in the hobby for a long time. [2] Because this fish is primarily nocturnal, it will retreat from brightness in the aquarium. When larger, these fish may prey upon smaller tankmates [2] as these fish have relatively large mouths for their size. This fish does well when kept in small groups when young, although as it ages, it becomes somewhat aggressive towards those of its own kind.
The family Notopteridae contains 10 species of osteoglossiform (bony-tongued) fishes, commonly known as featherbacks and knifefishes. These fishes live in freshwater or brackish environments in Africa and West South East and Southeast Asia.
The blind shark is one of two species of carpet sharks in the family Brachaeluridae, along with the bluegrey carpetshark. Found along the coast of eastern Australia, this nocturnal, bottom-dwelling species is common in rocky areas and seagrass beds from the intertidal zone to a depth of 140 m (460 ft). It often roams in tidal pools where it may be trapped by the receding tide, and can survive for an extended period out of water.
The bluegrey carpetshark or Colclough's shark, is an uncommon species of carpet shark endemic to shallow inshore waters off northeastern Australia. It is one of the two extant members of the family Brachaeluridae. The bluegrey carpetshark has a stocky body with a wide, slightly flattened head, dorsally placed eyes, and a pair of long barbels with posterior skin flaps. It has large pectoral fins, two dorsal fins of unequal size placed far back on the body, and a sizeable space between the anal fin and the base of the caudal fin. Growing to 76 cm (30 in) long, this species has a black-and-white colour pattern as a juvenile, which largely fades with age such as that adults are brownish.
The smoothback angelshark is an angelshark of the family Squatinidae found in the eastern Atlantic and Mediterranean.
Sorubim is a small genus of long-whiskered catfish native to tropical South America. A number of characteristics allows the differentiation of each species in the genus. Sorubim species are important food fish in South America and are highly significant to fisheries of some areas; however, harvests of these fish are not identified as much as other, more popular food fishes such as Colossoma, Arapaima, and Brachyplatystoma. Some species of this family are popular aquarium fish.
The zig-zag eel, also known as the Baim,tire-track, tire-track spiny- or marbled spiny eel, is a species of freshwater ray-finned fish in the family Mastacembelidae. It is native to the riverine systems of the Indian Subcontinent, Sri Lanka, Malaysia,Thailand, Vietnam, Cambodia, Indonesia, and other parts of South and Southeast Asia. The species was initially described as Macrognathus armature. Other common names for this popular captive species include the leopard spiny eel and white-spotted spiny eel.
The clown featherback, also known as the clown knifefish and spotted knifefish, is a nocturnal species of tropical fish with a long, knife-like body. This knifefish is native to freshwater habitats in Cambodia, China, Hong Kong, Laos, Macau, Thailand, and Vietnam, but it has also been introduced to regions outside its native range. It is one of the world's most invasive species.
Leiarius is a genus of long-whiskered catfishes native to South America. Most of the genus' species are found in the aquarium hobby as ornamental fish.
Denticetopsis is a genus of catfishes of the family Cetopsidae.
Synodontis nigrita, known as the false upside down catfish, is a species of upside-down catfish that occurs widely in northern Africa. It was first described by French zoologist Achille Valenciennes in 1840. The type specimen is in the Muséum National d' Histoire Naturelle de Paris.
Nannostomus trifasciatus,, commonly known as the three-lined or three-stripe pencilfish, is a freshwater species of fish belonging to the characin family Lebiasinidae. They are popular in the aquarium trade due to their small size, beautiful color pattern, and relative hardiness.
The hornyhead chub is a small species of minnow in the family Cyprinidae of order Cypriniformes. It mainly inhabits small rivers and streams of the northern central USA, up into Canada. The adults inhabit faster, rocky pools of rivers.
Sternarchogiton labiatus is a species of weakly electric knifefish in the family Apteronotidae. Its species name labiatus comes from the Latin labium, meaning "lip", referring to a distinctive three-lobed structure on its lower lips. S. labiatus is only known from the Tefé River, at a depth of 6–14 m (20–46 ft), and from the lower Rio Negro, in the Amazon River basin. They have been captured from both whitewater and blackwater habitats.
Malapterurus beninensis is a species of electric catfish native to the African nations of Angola, Benin, Cameroon, the Democratic Republic of the Congo, the Republic of the Congo, Equatorial Guinea, Gabon, Ghana, Nigeria and Togo. This species grows to a length of 22 cm (9 in) SL. Its habitat is lowland marshes, rivers, and lakes.
The reticulated knifefish is a species of freshwater fish in the family Notopteridae, the featherbacks, found in tropical West Africa. It reaches a maximum length of 80 cm (31 in) and a reported weight of 1.3 kg (2.9 lb).
Ostorhinchus fasciatus, commonly known as the broad-banded cardinalfish, is a marine fish native to the Indian and Pacific Oceans which is a Lessepsian migrant to the eastern Mediterranean through the Suez Canal from the Red Sea, it was first recorded off Israel in 2008 and has now reached the southern coast of Turkey. It has a number of vernacular names including barred striped cardinalfish, four-banded soldier-fish, striped cardinalfish and twostripe cardinalfish.
Gymnotus choco, commonly known as the cuchillo, is an electric knifefish. G. choco is distinguished from its cogenerate species group by a color pattern possessing pale yellow bands oriented obliquely, wherein the interband margins are wavy or even irregular; one to three Y-shaped dark bands occur on its body's posterior section; and its pale bands do not extend above the fish's lateral line on its body's anterior two-thirds. G. choco is most similar to G. paraguensis from the Pantanal in Brazil and Paraguay. From the latter, it is distinguished by having a narrower mouth, a more cylindrical body, and a longer preanal distance.
Guyanancistrus nassauensis is a species of catfish belonging to the family Loricariidae, the suckermouth armored catfishes. It is discovered in 2005 and formally described in 2018. G. nassauensis is a rare species, highly endemic to the Nassau Mountains in Suriname, and is threatened with extinction by proposed or ongoing mining activities.
Archolaemus luciae is a species of glass knifefish endemic to Brazil where it is found in the Rio Jari, the Rio Trombetas and the Rio Tapajós basins in the eastern Amazon. Also found in the Rio Araguari. This species reaches a length of 49.7 cm (19.6 in).
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