The Gymnotiformes are an order of teleost bony fishes commonly known as Neotropical knifefish or South American knifefish. They have long bodies and swim using undulations of their elongated anal fin. Found almost exclusively in fresh water, these mostly nocturnal fish are capable of producing electric fields to detect prey, for navigation, communication, and, in the case of the electric eel, attack and defense. A few species are familiar to the aquarium trade, such as the black ghost knifefish, the glass knifefish, and the banded knifefish.
The ghost knifefishes are a family, Apteronotidae, of ray-finned fishes in the order Gymnotiformes. These fish are native to Panama and South America. They inhabit a wide range of freshwater habitats, but more than half the species in the family are found deep in rivers where there is little or no light.
An electric fish is any fish that can generate electric fields. Most electric fish are also electroreceptive, meaning that they can sense electric fields. The only exception is the stargazer family (Uranoscopidae). Electric fish, although a small minority of all fishes, include both oceanic and freshwater species, and both cartilaginous and bony fishes.
The black ghost knifefish is a tropical fish belonging to the ghost knifefish family (Apteronotidae). They originate in freshwater habitats in South America where they range from Venezuela to the Paraguay–Paraná River, including the Amazon Basin. They are popular in aquaria. The fish is all black except for two white rings on its tail, and a white blaze on its nose, which can occasionally extend into a stripe down its back. It moves mainly by undulating a long fin on its underside. It will grow to a length of 18"-20". Only a fish for those with large aquariums, minimum 100 gallons.
Knifefish may refer to several knife-shaped fishes:
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 South and Southeast Asia.
The Hypopomidae are a family of fishes in the order Gymnotiformes known as the bluntnose knifefish. They may also be called grass or leaf knifefishes. These electric fish are not often eaten, of little commercial importance, rarely kept as aquarium fish, and poorly studied; however, species in this family may constitute a significant fraction of the biomass in the areas they inhabit.
The African brown knifefish, 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.
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, Taiwan, 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.
Chitala is a genus of fish of the family Notopteridae. This genus contains six species, in which some are important in aquaculture and the aquarium industry. They are commonly known as the Asian knifefishes or featherbacks. They are native to freshwater in South and Southeast Asia.
The brown ghost knifefish is a species of weakly electric knifefish in the family Apteronotidae. Only the brown ghost knifefish, a vertebrate, has been proven to have negligible brain aging thus far. In the current study, the basic development patterns of this species are examined, and the hypothesis that minimum senescence is associated with indeterminate growth and the lack of reproductive senescence is assessed. They are a hardy species that eats tiny fish, crustaceans, and insect larvae in the nature, but in an aquarium, they often take to frozen foods rather quickly.
Chitala chitala is a knifefish from Bangladesh, India, Nepal, and Pakistan, found in the Brahmaputra, Indus, Ganges and Mahanadi River basins. It is sometimes known as the Indian featherback or Indian knifefish. In the past, it frequently included several related Chitala species, but these are now regarded as separate species. The main species confused with this species is C. ornata ; a Southeast Asian species seen regularly in the aquarium trade. The true C. chitala is very rare in the aquarium trade.
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).
Sternarchorhynchus is a genus of ghost knifefishes with a long, decurved snout that are found in river basins in tropical South America.
Hypopygus is a genus of South American gymnotiform knifefishes native to the Amazon, Orinoco and upper Paraguay basins, as well as rivers in the Guianas. They are often common, and found near submerged roots, aquatic vegetation and leaf-litter in streams, edges of rivers and floodplains. They are regularly found among vegetation in floating meadows, a habitat that often contains little oxygen, but they are well-adapted to this.
Steatogenys is a genus of gymnotiform knifefishes found in the Amazon, Orinoco and Essequibo river basins in tropical South America. The widespread and common S. elegans is found in a wide range of habitats, from the shallow essentially static waters such as floodplain lakes to fast-flowing rivers as deep as 50 m (160 ft). The two remaining species are less common and widespread, with A. duidae found mainly in small streams running through terra firme forests and S. ocellatus among submerged roots and branches in static or slow-flowing blackwater habitats. All three are regularly found among vegetation in floating meadows, a habitat that often contains little oxygen, but they are well-adapted to this.
Stegostenopos cryptogenes is a species of bluntnose knifefish endemic to Brazil where it is found in the Rio Negro basin. This species can reach a total length of up to 15 cm (5.9 in). It is the only member of the genus Stegostenopos according to FishBase, but studies have shown that it belongs in Hypopygus and this is followed by the Catalog of Fishes.
Rhamphichthys(Rhamphos = Greek for beak and Ichthys = Greek for fish) is a genus of fish that includes the South American sand knifefish. These fish are eel shaped with a distinct beak like snout which gave them their name. Like most other knifefish Rhamphichthys species have electrical organs that help them live in the murky waters of South America. Currently there are 10 recognized species of Rhamphichthys, although many changes have been made in their taxonomy since their original discovery.
Hypopygus lepturus is a species of bluntnose knifefish and is commonly found in Northern South America. It is part of the family Hypopomidae and is occasionally kept as an aquarium fish. It lives in freshwater and grows up to 10 centimeters long.
