Naked-back knifefish
Encyclopedia
The naked-back knifefishes are a family (Gymnotidae) of knifefish
es (knivefish) that are found only in fresh water
s of Central America
and South America
. All have organ
s adapted to the exploitation of bioelectricity. The family has 33 valid species in two genera. There are a number of undescribed species known in museum collections.
These fish are nocturnal and mostly occur in quiet waters from deep rivers to swamps. In strongly-flowing waters they may bury themselves.
The sole member of Electrophorus is the electric eel
, which produces both strong (up to 600 volts) and weak (<1 V) electric discharges, for use in predation and communication/navigation, respectively. The electric eel is the largest of the gymnotiform fishes, growing up to more than 2 metres (6.6 ft) length. Species of Gymnotus
reach up to about 100 centimetres (3.3 ft) in length.
Knifefish
Knifefish may refer to several knife-shaped fishes:* The Neotropical or weakly electric knifefishes, order Gymnotiformes, containing five families:** Family Gymnotidae ** Family Rhamphichthyidae...
es (knivefish) that are found only in fresh water
Fresh Water
Fresh Water is the debut album by Australian rock and blues singer Alison McCallum, released in 1972. Rare for an Australian artist at the time, it came in a gatefold sleeve...
s of Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
. All have organ
Organ (anatomy)
In biology, an organ is a collection of tissues joined in structural unit to serve a common function. Usually there is a main tissue and sporadic tissues . The main tissue is the one that is unique for the specific organ. For example, main tissue in the heart is the myocardium, while sporadic are...
s adapted to the exploitation of bioelectricity. The family has 33 valid species in two genera. There are a number of undescribed species known in museum collections.
These fish are nocturnal and mostly occur in quiet waters from deep rivers to swamps. In strongly-flowing waters they may bury themselves.
Physical characteristics
Like the other gymnotiforms, Gymnotids have a classic knifefish body. The body is long and eel-like, the dorsal fin and pectoral fins are absent, and the anal fin is extremely long and used for movement.The sole member of Electrophorus is the electric eel
Electric eel
The electric eel , is an electric fish, and the only species of the genus Electrophorus. It is capable of generating powerful electric shocks, of up to six hundred volts, which it uses for both hunting and self-defense. It is an apex predator in its South American range...
, which produces both strong (up to 600 volts) and weak (<1 V) electric discharges, for use in predation and communication/navigation, respectively. The electric eel is the largest of the gymnotiform fishes, growing up to more than 2 metres (6.6 ft) length. Species of Gymnotus
Gymnotus
Gymnotus is the among the most species-rich group of electric knifefishes found in the Amazon. Some Gymnotus species live in the leaf litter and root tangles of river banks. Other species are specialized to live on floodplains within the rootmats of floating meadows. Several species are broadly...
reach up to about 100 centimetres (3.3 ft) in length.
Species
There are 34 species in two genera:- Genus ElectrophorusElectric eelThe electric eel , is an electric fish, and the only species of the genus Electrophorus. It is capable of generating powerful electric shocks, of up to six hundred volts, which it uses for both hunting and self-defense. It is an apex predator in its South American range...
- Electric eelElectric eelThe electric eel , is an electric fish, and the only species of the genus Electrophorus. It is capable of generating powerful electric shocks, of up to six hundred volts, which it uses for both hunting and self-defense. It is an apex predator in its South American range...
, Electrophorus electricus (LinnaeusCarolus LinnaeusCarl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
, 1766).
- Electric eel
- Genus GymnotusGymnotusGymnotus is the among the most species-rich group of electric knifefishes found in the Amazon. Some Gymnotus species live in the leaf litter and root tangles of river banks. Other species are specialized to live on floodplains within the rootmats of floating meadows. Several species are broadly...
- Gymnotus anguillaris Hoedeman, 1962.
- Gymnotus arapaima Albert & Crampton, 2001.
- Gymnotus ardilai Maldonado-Ocampo & Albert, 2004.
- Gymnotus bahianus Campos-da-Paz & Costa, 1996.
- Banded knifefishBanded knifefishThe Banded knifefish is a knifefish native to South America.-Physical characteristics:The banded knifefish is gray fish with a band of large black spots outlined with yellow on either side. they can get up to 60 cm long.-Range and habitat:The banded knifefish lives in lakes and streams in...
, Gymnotus carapo LinnaeusCarolus LinnaeusCarl Linnaeus , also known after his ennoblement as , was a Swedish botanist, physician, and zoologist, who laid the foundations for the modern scheme of binomial nomenclature. He is known as the father of modern taxonomy, and is also considered one of the fathers of modern ecology...
, 1758. - Gymnotus cataniapo Mago-Leccia, 1994.
- Gymnotus chimarrao
- Gymnotus choco Albert, Crampton & Maldonado, 2003.
- Gymnotus coatesi La Monte, 1935.
- Gymnotus coropinae Hoedeman, 1962.
- Gymnotus curupira Crampton, Thorsen & Albert, 2005.
- Gymnotus cylindricus La Monte, 1935.
- Gymnotus diamantinensis Campos-da-Paz, 2002.
- Gymnotus esmeraldas Albert & Crampton, 2003.
- Gymnotus henni Albert, Crampton & Maldonado, 2003.
- Gymnotus inaequilabiatus (ValenciennesAchille ValenciennesAchille Valenciennes was a French zoologist.Valenciennes was born in Paris, and studied under Georges Cuvier. Valenciennes' study of parasitic worms in humans made an important contribution to the study of parasitology...
, 1842). - Gymnotus javari Albert, Crampton & Hagedorn, 2003.
- Gymnotus jonasi Albert & Crampton, 2001.
- Spotted knifefish, Gymnotus maculosus Albert & Miller, 1995.
- Gymnotus mamiraua Albert & Crampton, 2001.
- Gymnotus melanopleura Albert & Crampton, 2001.
- Gymnotus obscurus Crampton, Thorsen & Albert, 2005.
- Gymnotus onca Albert & Crampton, 2001.
- Gymnotus panamensis Albert & Crampton, 2003.
- Gymnotus pantanal Fernandes, Albert, Daniel-Silva, Lopes, Crampton & Almeida-Toledo, 2005.
- Gymnotus pantherinus (SteindachnerFranz SteindachnerFranz Steindachner was an Austrian zoologist.- Work and career :Being interested in natural history, Steindachner took up the study of fossil fishes on the recommendation of his friend Eduard Suess...
, 1908). - Gymnotus paraguensis Albert & Crampton, 2003.
- Gymnotus pedanopterus Mago-Leccia, 1994.
- Gymnotus stenoleucus Mago-Leccia, 1994.
- Gymnotus sylvius Albert & Fernandes-Matioli, 1999.
- Gymnotus tigre Albert & Crampton, 2003.
- Gymnotus ucamara Crampton, Lovejoy & Albert, 2003.
- Gymnotus varzea Crampton, Thorsen & Albert, 2005.