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Knifefish (other)
Knifefish may refer to several knife-shaped fishes: *The Neotropical or weakly electric knifefishes, order Gymnotiformes, containing five families: **Family Gymnotidae (banded knifefishes and the electric eel) **Family Rhamphichthyidae (sand knifefishes) **Family Hypopomidae (bluntnose knifefishes) **Family Sternopygidae (glass and rat-tail knifefishes) **Family Apteronotidae (ghost knifefishes) *The featherbacks, family Notopteridae. *The aba, ''Gymnarchus niloticus'' *Four other unrelated fish species not in any of the above families: ** Grey knifefish, ''Bathystethus cultratus''. ** Blue knifefish, ''Labracoglossa nitida''. **Collared knifefish or finscale razorfish, ''Cymolutes torquatus''. ** Jack-knifefish, ''Equetus lanceolatus''. See also *Knifefish (robot) The Knifefish is an autonomous unmanned underwater vehicle (UUV) under development by General Dynamics Mission Systems and Bluefin Robotics for the United States Navy. It is a propeller-driven minesweeping robot d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weakly Electric Fish
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. Electric fish, although a small minority, include both oceanic and freshwater species, and both cartilaginous and bony fishes. Electric fish produce their electrical fields from an electric organ. This is made up of electrocytes, modified muscle or nerve cells, specialized for producing strong electric fields, used to locate prey, for defence against predators, and for signalling, such as in courtship. Electric organ discharges are two types, pulse and wave, and vary both by species and by function. Electric fish have evolved many specialised behaviours. The predatory African sharptooth catfish eavesdrops on its weakly electric mormyrid prey to locate it when hunting, driving the prey fish to develop electric signals that are harder to detect. Bluntnose knifefishes produce an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gymnotiformes
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 (the only exceptions are species that occasionally may visit brackish water to feed), these mostly nocturnal fish are capable of producing electric fields to detect prey, for navigation, communication, and, in the case of the electric eel (''Electrophorus electricus''), attack and defense. A few species are familiar to the aquarium trade, such as the black ghost knifefish (''Apteronotus albifrons''), the glass knifefish (''Eigenmannia virescens''), and the banded knifefish (''Gymnotus carapo''). Description Anatomy and locomotion Aside from the electric eel (''Electrophorus electricus''), Gymnotiformes are slender fish with narrow bodies and tapering tails, hence the common name of "knifefishes". They have neither pelvic fins nor dorsal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electric Eel
The electric eels are a genus, ''Electrophorus'', of neotropical freshwater fish from South America in the family Gymnotidae. They are known for their ability to stun their prey by generating electricity, delivering shocks at up to 860 volts. Their electrical capabilities were first studied in 1775, contributing to the invention in 1800 of the electric battery. Despite their name, electric eels are not closely related to the true eels (Anguilliformes) but are members of the electroreceptive knifefish order, Gymnotiformes. This order is more closely related to catfish. In 2019, electric eels were split into three species: for more than two centuries before that, the genus was believed to be monotypic, containing only ''Electrophorus electricus.'' They are nocturnal, air-breathing animals, with poor vision complemented by electrolocation; they mainly eat fish. Electric eels grow for as long as they live, adding more vertebrae to their spinal column. Males are larger than fem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhamphichthyidae
Sand knifefish are freshwater electric fish of the family Rhamphichthyidae, from freshwater habitats in South America. Just like most part of the members of the Gymnotiformes group, they also have elongated and compressed bodies and electric organs. The long anal fin actually extends from before the pectoral fins to the tip of the tail. There is no dorsal fin. Teeth are absent in the oral jaws and the snout is very long and tubular. The nostrils are very close together. This group is sometimes known as the tubesnout knifefishes for this reason. They are nocturnal and burrow in the sand during the day. Genera According to FishBase there are only three genera in this family, but a comprehensive molecular study from 2015 showed that two additional genera belong here (formerly in Hypopomidae, marked with stars* in list), and this has been followed by recent authorities. *'' Gymnorhamphichthys'' *'' Hypopygus''* *'' Iracema'' *'' Rhamphichthys'' *'' Steatogenys''* See also * Li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypopomidae
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. These fish originate from fresh water in Panama and South America. The Hypopomidae are confined to the humid neotropics, ranging the Río de la Plata of Argentina (35°S) to the Río Tuira of Panama (8°N). Hypopomids are known from the continental waters of all South American countries except Chile, and are most diverse in the Amazon Basin. Description Teeth are absent on the oral jaws. Unlike the closely related Rhamphichthyidae, species of this family do not have a tubular snout, but a blunt, short one. Also, the nostrils are well separated. This family contains the smallest gymnotiforms, ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apteronotidae
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 (typically deeper than ) where there is little or no light. The Apteronotidae should not be confused with the unrelated Notopteridae, which are also commonly called knifefishes. They are distinguished from other gymnotiform fishes by the presence of a caudal fin (all other families lack a caudal fin) as well as a fleshy dorsal organ represented by a longitudinal strip along the dorsal midline. They vary greatly in size, ranging from about in total length in the smallest species to in the largest. It has been claimed that ''Apteronotus magdalenensis'' is up to , but this is not supported by recent studies, which indicate that it does not surpass about . These nocturnal fish have small eyes. Also, sexual dimorph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Notopteridae
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. With the denotation of "knifefish", the notopterids should not be confused with Gymnotiformes, the electric knifefishes from South and Central America. Although their manner of swimming is similar and they are superficially similar in appearance, the two groups are not closely related. A few of the larger species, especially ''Chitala ornata'', are food fish and occasionally aquarium pets. The name is from Greek ''noton'' meaning "back" and ''pteron'' meaning "fin". Fossils The earliest fossils of this family are of '' Notopteridarum'' and ''Notopterus'' from the Late Cretaceous of India, about 70.6 to 66 million years ago. These fossils originate from the Rangapur microvertebrate site and Naskal microvertebrate site of Andhra Pradesh, which are part ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gymnarchus Niloticus
''Gymnarchus niloticus'' – commonly known as the ''aba'', ''aba aba'', frankfish, freshwater rat-tail, ''poisson-cheval'', or African knifefish – is an electric fish, and the only species in the genus ''Gymnarchus'' and the family Gymnarchidae within the order Osteoglossiformes. It is found in swamps, lakes and rivers in the Nile, Turkana, Chad, Niger, Volta, Senegal, and Gambia basins. Description and biology ''G. niloticus'' has a long and slender body, with no caudal, pelvic, or anal fins. The dorsal fin is elongated, running along the back of the fish towards the blunt, finless tail, and is the main source of propulsion. It grows up to in length and in weight. ''G. niloticus'' is nocturnal and has a poor vision. Instead, it navigates and hunts smaller fish using a weak electric field, as demonstrated by the zoologist Hans Lissmann in 1950, when he noticed that it could swim equally well forwards or backwards, clearly relying on a sense other than vision. This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grey Knifefish
The grey knifefish (''Bathystethus cultratus'') is a species of sea chub native to the Pacific Ocean from Australia to New Zealand and the Kermadec Islands. This species is a plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ... eater which swims constantly within a few meters of the surface of the ocean. This species can reach a length of . References Scorpidinae Endemic marine fish of New Zealand Fish described in 1801 {{Perciformes-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blue Knifefish
The blue knifefish (''Labracoglossa nitida'') is a species of marine ray-finned fish, a member of the subfamily Scorpidinae of the sea chub family Kyphosidae. It is native to the Pacific Ocean waters off eastern Australia over to New Zealand, where it occurs at depths reaching from the surface to in inshore waters over reefs A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes— deposition of sand, wave erosion planing down rock out .... It can reach a length of , though most do not exceed . References Scorpidinae Fish described in 1916 {{Perciformes-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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