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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] |
Sternarchogiton Nattereri
''Sternarchogiton nattereri'' is a species of weakly electric knifefish in the family Apteronotidae. It is native to the Amazon River system and feeds on sponges. Unlike other members of the genus '' Sternarchogiton'', there is pronounced sexual dimorphism in ''S. nattereri'', with reproductively mature males developing strong external teeth on tips of their jaws. These males are so different from the females and juveniles that they were thought to be a different genus and species, the "tooth-lip knifefish" ''Oedemognathus exodon'', for over 40 years. Distribution and habitat ''S. nattereri'' is restricted to large river channels in the lowlands of the Amazon basin. Its habitat ranges from high-conductivity, sediment-rich whitewater rivers such as the Rio Solimões, to low-conductivity, sediment-poor blackwaters such as the Rio Negro. It is one of the most common gymnotiforms in Rio Solimões. Description ''S. nattereri'' has a laterally compressed, knife-shaped body. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthosternarchus Tamandua
''Orthosternarchus tamandua'', the tamandua knifefish, is a species of weakly electric knifefish in the family Apteronotidae, native to the deep river channels of the Amazon basin. This species is characterized by its whitish-pink color (no dark pigment), long tubular snout, long dorsal appendage, and tiny, bilaterally asymmetrical eyes. Systematics ''O. tamandua'' was originally described as ''Sternarchus tamandua'' by George Albert Boulenger in 1880; its species name is from the Tupi word ''tamanduá'', meaning "anteater", in reference to its long snout. In 1905, Eigenmann and Ward placed this species in the genus '' Sternarchorhamphus'', though noting that it may represent a distinct genus. In 1913, Max M. Ellis placed this species into its own genus ''Orthosternarchus'', from the Greek ''orthos'' ("straight"), ''sternon'' ("chest"), and ''archos'' ("rectum"), referring to the straight snout and the forward placement of the urogenital opening. Ellis saw ''O. tamandua'' as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apteronotus Magdalenensis
''Apteronotus'' is a genus of weakly electric knifefish in the family Apteronotidae, distinguished by the presence of a tiny tail fin. This genus is restricted to tropical and subtropical South America (Amazon, Orinoco, Río de la Plata and Magdalena basins, as well as rivers in western Colombia and the Guianas) and Panama where found in a wide range of freshwater habitats. They feed on small animals. Depending on the exact species, they reach a total length of up to about . Although it has been claimed that ''A. magdalenensis'' is up to long, this is not supported by recent studies and likely the result of confusion with '' Sternopygus aequilabiatus''. Members of ''Apteronotus'' fall into three species groups based on their morphology: the ''A. albifrons'' group have a rounded snout and are black or dark brown with a contrasting light stripe on the top of the head, and bands on the tail and at its base, the ''A. leptorhynchus'' group have an elongate, slender snout (especi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apteronotus
''Apteronotus'' is a genus of weakly electric knifefish in the family Apteronotidae, distinguished by the presence of a tiny tail fin. This genus is restricted to tropical and subtropical South America (Amazon, Orinoco, Río de la Plata The Río de la Plata (, "river of silver"), also called the River Plate or La Plata River in English, is the estuary formed by the confluence of the Uruguay River and the Paraná River at Punta Gorda. It empties into the Atlantic Ocean and fo ... and Magdalena River, Magdalena basins, as well as rivers in western Colombia and the Guianas) and Panama where found in a wide range of freshwater habitats. They feed on small animals. Depending on the exact species, they reach a total length of up to about . Although it has been claimed that ''A. magdalenensis'' is up to long, this is not supported by recent studies and likely the result of confusion with ''Sternopygus aequilabiatus''. Members of ''Apteronotus'' fall into three species groups ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sternarchella
''Sternarchella'', the bulldog knifefish, is a genus of ghost knifefishes found at depths of in the main channel of large rivers in South America. Most are from the Amazon basin, but ''S. orthos'' is found both in the Amazon and Orinoco, ''S. orinoco'' is restricted to the Orinoco and ''S. curvioperculata'' restricted to the upper Paraná basin (however, the last species likely belongs in another genus, possibly ''Apteronotus''). They are often common in their habitat.Lundberg, J.G., Cox Fernandes, C., Campos-Da-Paz, R. & Sullivan, J.P. (2013): ''Sternarchella calhamazon'' n. sp., the Amazon’s most abundant species of apteronotid electric fish, with a note on the taxonomic status of ''Sternarchus capanemae'' Steindachner, 1868 (Gymnotiformes, Apteronotidae). ''Proceedings of the Academy of Natural Sciences of Philadelphia, 162: 157-173.'' They have a blunt or pointed snout (none have the greatly elongated snout found in some other knifefish), reduced pigmentation and reach u ... [...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 ... |
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