Sternopygidae

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Megaclassis: Osteichthyes
Superclassis/Classis: Actinopterygii
Classis/Subclassis: Actinopteri
Subclassis/Infraclassis: Neopterygii
Infraclassis: Teleostei
Megacohors: Osteoglossocephalai
Supercohors: Clupeocephala
Cohors: Otomorpha
Subcohors: Ostariophysi
Sectio: Otophysa
Ordo: Gymnotiformes

Familia: Sternopygidae
Genera (7): Archolaemus – Distocyclus – Eigenmannia – Japigny – Rhabdolichops – Sternopygus – †Humboldtichthys
References

Mago Leccia, Francisco. 1976: “Los peces Gymnotiformes de Venezuela: un estudio preliminar para la revisión del grupo en la América del Sur”. Universidad Central de Venezuela. Tesis Doctoral. Caracas – Venezuela 376p.
Mago Leccia, Francisco. 1978: “Los peces de la Familia Sternopygidae de Venezuela”. Acta Científica Venezolana. 29 (supl.1):1-91.
Meunier, F.J.; Jégu, M.; Keith, P. 2011: A new genus and species of neotropical electric fish, Japigny kirschbaum (Gymnotiformes: Sternopygidae), from French Guiana. Cybium, 35(1): 47–53. abstract only seen

Links

Froese, R. and D. Pauly. Editors. 2006. FishBase, version (02/2006). [1]

Glass knifefishes are fishes in the family Sternopygidae in the order Gymnotiformes. Species are also known as rattail knifefishes.[1]

These fishes inhabit freshwater streams and rivers in Panama and South America.[1] Many sternopygid species are specialized for life in the deep (more than 20 m or 66 ft) swiftly moving waters of large river channels, like that of the Amazon and its major tributaries[2] where they have been observed swimming vertically.[3] Sternopygus species inhabit both streams and rivers.[4]

Many species are highly compressed laterally and translucent in life.[4] These fish have villiform (brush-like) teeth on the upper and lower jaws. The snout is relatively short. The eyes are relatively large, with a diameter equal to or greater than the distance between nares. The anal fin originates at the isthmus (the strip of flesh on the ventral surface between the gill covers). The maximum length is 140 cm (55 in) in Sternopygus macrurus.

Eigenmannia vicentespelaea is the only cave-dwelling gymnotiform. Humboldtichthys kirschbaumi (formerly genus Ellisella) from Upper Miocene of Bolivia is the only fossil gymnotiform.[1]

These fish have a tone-like electric organ discharge (EOD) that occurs monophasically.

Some of these species are aquarium fishes.
Genera

There are 30 living species of glass knifefish, grouped into six genera:[5]

Archolaemus
Distocyclus
Eigenmannia
†Humboldtichthys (fossil, Upper Miocene)
Japigny
Rhabdolichops
Sternopygus

References

Nelson, Joseph, S. (2006). Fishes of the World. John Wiley & Sons, Inc. ISBN 978-0-471-25031-9.
Crampton, W.G.R., Hulen, K., & Albert, J.S. (2004). "Sternopygus branco, a new species of Neotropical electric fish (Gymnotiformes: Sternopygidae) from the lowland Amazon basin, with descriptions of ecology and electric organ discharges." Copeia 2004(2): 244-258.
Kate Humble (2005). Amazon Abyss (TV-Series). BBC.
Froese, Rainer, and Daniel Pauly, eds. (2007). "Sternopygidae" in FishBase. Apr 2007 version.

Froese, Rainer, and Daniel Pauly, eds. (2011). "Sternopygidae" in FishBase. December 2011 version.