''Sternopygus'' is a genus of

glass knifefish Glass knifefishes are fishes in the family Sternopygidae in the order Gymnotiformes. Species are also known as rattail knifefishes. These fishes inhabit freshwater streams and rivers in Panama and South America. Many species are specialized for ...

es found in tropical and subtropical

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 ...

(south to the

Río de la Plata Basin The Río de la Plata basin (, ), more often called the River Plate basin in scholarly writings, sometimes called the Platine basin or Platine region, is the Hydrography, hydrographical area in South America that drains to the Río de la Plata. I ...

), and

Panama Panama, officially the Republic of Panama, is a country in Latin America at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and ...

. It is the only extant extant member of the subfamily Sternopyginae, with the related fossil genus '' Humboldtichthys'' also known from Bolivia. They inhabit a wide range of freshwater habitats, from fast-flowing rivers to essentially static waters in floodplains, and shallow habitats to the bottom of deep rivers. ''S. macrurus'' will even visit

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

mangroves A mangrove is a shrub or tree that grows mainly in coastal saline or brackish water. Mangroves grow in an equatorial climate, typically along coastlines and tidal rivers. They have particular adaptations to take in extra oxygen and remove sal ...

to feed. They are medium to large knifefish, with a maximum total length of depending on the exact species. They feed on invertebrates, small fish and fruits. Most members of

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 ...

are

nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...

, but ''Sternopygus'' are both nocturnal and diurnal.

Species

There are currently eleven recognized species in this genus. * ''

Sternopygus aequilabiatus ''Sternopygus'' is a genus of glass knifefishes found in tropical and subtropical South America (south to the Río de la Plata Basin), and Panama. It is the only extant extant member of the subfamily Sternopyginae, with the related fossil genus ' ...

'' (

Humboldt Humboldt may refer to: People * Alexander von Humboldt, German natural scientist, brother of Wilhelm von Humboldt * Wilhelm von Humboldt, German linguist, philosopher, and diplomat, brother of Alexander von Humboldt Fictional characters * Hu ...

, 1805) * '' Sternopygus arenatus'' ( Eydoux & Souleyet, 1850) * '' Sternopygus astrabes'' Mago-Leccia, 1994 * '' Sternopygus branco'' Crampton,

Hulen Hulen ('The Cave') is a student-driven rock club in Bergen Bergen (, ) is a city and municipalities of Norway, municipality in Vestland county on the Western Norway, west coast of Norway. Bergen is the list of towns and cities in Norway, sec ...

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 ...

, 2004 * '' Sternopygus dariensis''

Meek Meekness is an attribute of human nature and behavior that has been defined as an amalgam of righteousness, inner humility, and patience. Meekness has been contrasted with humility alone insomuch as humility simply refers to an attitude towards o ...

Hildebrand Hildebrand is a character from Germanic heroic legend. ''Hildebrand'' is the modern German form of the name: in Old High German it is ''Hiltibrant'' and in Old Norse ''Hildibrandr''. The word ''hild'' means "battle" and ''brand'' means "sword" ...

1916 * '' Sternopygus macrurus'' (

Bloch Bloch is a surname of German origin. Notable people with this surname include: A *Adele Bloch-Bauer (1881–1925), Austrian entrepreneur *Albert Bloch (1882–1961), American painter *Alexandre Bloch (1857–1919), French painter *Alfred Bloch ( ...

& J. G. Schneider, 1801) (Longtail knifefish) * '' Sternopygus obtusirostris''

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 ...

, 1881 * '' Sternopygus pejeraton'' L. P. Schultz, 1949 * ''

Sternopygus sabaji ''Sternopygus'' is a genus of glass knifefishes found in tropical and subtropical South America (south to the Río de la Plata Basin), and Panama. It is the only extant extant member of the subfamily Sternopyginae, with the related fossil genus ' ...

'' Torgersen & Albert, 2022Kevin T. Torgersen and James S. Albert. 2022. A New Species of Sternopygus (Gymnotiformes: Sternopygidae) from the Atlantic Coast of the Guiana Shield. Ichthyology & Herpetology. 110(4), 714-727. DOI: 10.1643/i2022013 * ''

Sternopygus sarae ''Sternopygus'' is a genus of glass knifefishes found in tropical and subtropical South America (south to the Río de la Plata Basin), and Panama. It is the only extant extant member of the subfamily Sternopyginae, with the related fossil genus ' ...

'' Torgersen, Galindo-Cuervo, Reis & Albert, 2023 * '' Sternopygus xingu'' Albert & W. L. Fink, 1996

References

Sternopygidae Ray-finned fish genera Taxa named by Johannes Peter Müller Taxa named by Franz Hermann Troschel {{Gymnotiformes-stub