''Sternarchella'', the bulldog knifefishes, is a genus of

ghost knifefish The ghost knifefishes consist of the family Apteronotidae, which are 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 specie ...

es found at depths of in the main channel of large rivers in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

. Most are from the

Amazon Amazon most often refers to: * Amazon River, in South America * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon (company), an American multinational technology company * Amazons, a tribe of female warriors in Greek myth ...

basin, but ''S. orthos'' is found both in the Amazon and

Orinoco The Orinoco () is one of the longest rivers in South America at . Its drainage basin, sometimes known as the Orinoquia, covers approximately 1 million km2, with 65% of it in Venezuela and 35% in Colombia. It is the List of rivers by discharge, f ...

, ''S. orinoco'' is restricted to the Orinoco and ''S. curvioperculata'' restricted to the upper

Paraná Paraná, Paranã or Parana may refer to: Geology * Paraná Basin, a sedimentary basin in South America Places In Argentina *Paraná, Entre Ríos, a city * Paraná Department, a part of Entre Ríos Province In Brazil *Paraná (state), a state ...

basin (however, the last species likely belongs in another genus, possibly ''

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 and ...

''). 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 up to in total length depending on the species. They feed on invertebrates and small fish.

Species

The following species are currently placed in this genus. Two species that formerly comprised their own genus ''

Magosternarchus ''Magosternarchus'' is a genus of weakly electric fish, weakly electric Gymnotiformes, knifefish in the family Apteronotidae, containing two species. They are endemic to Brazil, occurring in large river channels in the Amazon River basin. Both sp ...

'' were recently included in ''Sternarchella'' * '' Sternarchella calhamazon'' Lundberg, Cox Fernandes, Campos-da-Paz &

Sullivan Sullivan may refer to: People Characters * Chloe Sullivan, from the television series ''Smallville'' * Colin Sullivan, a character in the film ''The Departed'', played by Matt Damon * Harry Sullivan (''Doctor Who''), from the British science f ...

, 2013 * '' Sternarchella duccis'' Lundberg, Cox Fernandes &

Albert Albert may refer to: Companies * Albert Computers, Inc., a computer manufacturer in the 1980s * Albert Czech Republic, a supermarket chain in the Czech Republic * Albert Heijn, a supermarket chain in the Netherlands * Albert Market, a street mar ...

* '' Sternarchella orinoco'' Mago-Leccia, 1994 * '' Sternarchella orthos'' Mago-Leccia, 1994 * '' Sternarchella patriciae'' K. M. Evans, Crampton & Albert 2017 * '' Sternarchella raptor'' Lundberg, Cox Fernandes & Albert} * '' Sternarchella rex'' Evans, Crampton & Albert 2017 * '' Sternarchella schotti'' (

Steindachner Franz Steindachner (11 November 1834 in Vienna – 10 December 1919 in Vienna) was an Austrian zoologist, ichthyologist, and herpetologist. He published over 200 papers on fishes and over 50 papers on reptiles and amphibians. Steindachner descri ...

, 1868) * '' Sternarchella sima'' Starks, 1913 One taxon, '' Sternarchella curvioperculata'', described by in 1968 is a ''

Species inquirenda In biological classification, a ''species inquirenda'' is a species of doubtful identity requiring further investigation. The use of the term in English-language biological literature dates back to at least the early nineteenth century. The ter ...

'' which is probaly best classified as belonging to ''

''.

References

Apteronotidae Fish of South America Ray-finned fish genera Taxa named by Carl H. Eigenmann {{Gymnotiformes-stub