Scientists have described two new species of deepwater electric knifefishes from the lowland portions of the Amazon River.
The two new species are members of the ghost knifefish family Apteronotidae, and have been named Sternachogiton labiatus and S. preto by Carlos de Santana and William Crampton in a revision of the genus published in the most recent issue of the journal Copeia.
Sternachogiton labiatus is named after an unusual three-lobed structure on the lowe rlip (labium = lip), and is known from the Rio Tefé and Rio Negro drainages in the Amazon basin.
Sternachogiton preto is named after its dark coloration, the name coming from the Portuguese for black. It is known from the Amazon basin in Brazil and northeast Peru, and the Orinoco basin in Venezuela.
Sternachogiton labiatus is diagnosed from all congeners by the presence of hard, prominent, three-lobed structure on the lower lips, two rows of conical teeth on the dentary, a medial ridge on the cleithrum, the possession of only one ossified basibranchial (the first) with posterior ones cartilaginous, 156168 anal-fin rays and light speckling of brown on the pectoral and anal fins.
Sternachogiton preto is diagnosed from all congeners in having a very dark brown or purplish black live body coloration, black pectoral-, anal- and caudal-fin membranes, five long conical teeth on the premaxilla, one row of conical teeth on the dentary, supracleithrum and posttemporal fused, and anterior portion of the coracoid falling short of the anterior edge of the cleithrum.
The revision of the genus recognizes two other species: S. porcinum from the Amazon River basin in Peru and the Orinoco River basin in Venezuela, and S. nattereri from the lowlands of the Amazon River basin.
The authors state that the function of the three-lobed structure on the lower lip of S. labiatus is unknown, although it may possibly used in electroreception.
According to the authors, mature males of S. nattereri possess secondary sexual characteristics in the form of patches of teeth growing externally on the upper and lower jaws.
For more information, see the paper: de Santan, CD and WGR Crampton (2007) revision of the deep-channel electric fish genus Sternachogiton (Gymnotiformes: Apteronotidae). Copeia 2007 (2), 387402.
The two new species are members of the ghost knifefish family Apteronotidae, and have been named Sternachogiton labiatus and S. preto by Carlos de Santana and William Crampton in a revision of the genus published in the most recent issue of the journal Copeia.
Sternachogiton labiatus is named after an unusual three-lobed structure on the lowe rlip (labium = lip), and is known from the Rio Tefé and Rio Negro drainages in the Amazon basin.
Sternachogiton preto is named after its dark coloration, the name coming from the Portuguese for black. It is known from the Amazon basin in Brazil and northeast Peru, and the Orinoco basin in Venezuela.
Sternachogiton labiatus is diagnosed from all congeners by the presence of hard, prominent, three-lobed structure on the lower lips, two rows of conical teeth on the dentary, a medial ridge on the cleithrum, the possession of only one ossified basibranchial (the first) with posterior ones cartilaginous, 156168 anal-fin rays and light speckling of brown on the pectoral and anal fins.
Sternachogiton preto is diagnosed from all congeners in having a very dark brown or purplish black live body coloration, black pectoral-, anal- and caudal-fin membranes, five long conical teeth on the premaxilla, one row of conical teeth on the dentary, supracleithrum and posttemporal fused, and anterior portion of the coracoid falling short of the anterior edge of the cleithrum.
The revision of the genus recognizes two other species: S. porcinum from the Amazon River basin in Peru and the Orinoco River basin in Venezuela, and S. nattereri from the lowlands of the Amazon River basin.
The authors state that the function of the three-lobed structure on the lower lip of S. labiatus is unknown, although it may possibly used in electroreception.
According to the authors, mature males of S. nattereri possess secondary sexual characteristics in the form of patches of teeth growing externally on the upper and lower jaws.
For more information, see the paper: de Santan, CD and WGR Crampton (2007) revision of the deep-channel electric fish genus Sternachogiton (Gymnotiformes: Apteronotidae). Copeia 2007 (2), 387402.
