HumboldtichthysHumboldtichthys is an extinct genus of glass knifefishes from the MioceneYecua Formation of Bolivia. A single species is currently recognized: Humboldtichthys kirschbaumi. History and namingThe earliest remains of gymnotiform electric fish were discovered in the BolivianYecua Formation 95 km (59 mi) west-northwest of Santa Cruz by petroleum geologists and easily recognized to belong to a gymnotiform fish based on several characteristic anatomical features.
SternopygusSternopygus 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 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.
ArcholaemusArcholaemus is a genus of South American glass knifefishes, family Sternopygidae. They occur in fast-flowing sections of rivers, including rapids, in the Amazon, Tocantins, São Francisco and Araguari basins. Depending on the exact species, they reach up to about 20–50 cm (8–20 in) in total length. During the day they hide in rocky crevices, but during the night they are active and feed on small invertebrates such as aquatic insect larvae.
Eigenmannia vicentespelaeaEigenmannia vicentespelaea is a species of weakly electricknifefish in the familySternopygidae. Native to the São Domingoskarst area in central Brazil, it is the only known knifefish to exclusively inhabit caves. Measuring up to 21 cm (8.3 in) long, E. vicentespelaea can be distinguished from its relatives by its translucent body and reduced or absent eyes. As some individuals retain well-developed eyes, this fish may have colonized caves only recently in evolutionary time.
EigenmanniaEigenmannia is a genus of fish in the family Sternopygidae (glass knifefishes) native to tropical and subtropical South America (south to the Río de la Plata Basin), and Panama. They are typically found in slow-flowing streams, along the edge of large rivers, in deep river channels and in floodplains, and the genus also includes E. vicentespelaea, the only cave-adapted knifefish. Eigenmannia are often found near submerged roots, aquatic plants and floating meadows.
GymnotiformesThe Gymnotiformes are an order of teleost bony fishes commonly known as Neotropical knifefish or South American knifefish, which inhabit fresh water (the only exceptions are species that occasionally may visit brackish water to feed). These mostly nocturnal fish have long bodies and swim using undulations of their elongated anal fin.
CavefishCavefish or cave fish is a generic term for fresh and brackish water fish adapted to life in caves and other underground habitats. Related terms are subterranean fish, troglomorphic fish, troglobitic fish, stygobitic fish, phreatic fish, and hypogean fish. There are more than 200 scientifically described species of obligate cavefish found on all continents, except Antarctica. Although widespread as a group, many species have very small ranges and are threatened.Distocyclus conirostrisDistocyclus is a monospecific genus of freshwater ray-finned fish belonging to the family Sternopygidae, the glass knifefishes. The only species in the genus is Distocyclus conirostris which is found in the deep waters (3.8 to 28.3 m, 12 to 93 ft) of the Amazon basin, lower portions of the Potaro River and in major parts of the Rio Orinoco. They are typically found in flood basins, flooded forests, and main river channels.
AquariumAn aquarium (pl.: aquariums or aquaria) is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aquatic reptiles, such as turtles, and aquatic plants. The term aquarium, coined by English naturalist Philip Henry Gosse, combines the Latin root aqua, meaning "water," with the suffix -arium, meaning "a place for relating to or connected with."
South AmericaContinentScheme for geographical regions and subregions used by the United Nations Statistics DivisionSouth America is a continent entirely in the Western Hemisphere and most in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern subregion of the Americas.
PanamaCountry in Central AmericaPanama, officially the Republic of Panama, is a country located at the southern end of Central America in North America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and the Pacific Ocean to the south. Its capital and largest city is Panama City, whose metropolitan area is home to nearly half of the country's over 4 million inhabitants.
Fresh waterFresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mineral-rich waters, such as chalybeate springs.*As an Amazon Associate I earn from qualifying purchases.