Revision Of The Deep-Channel Electric Fish Genus Sternarchogiton (Gymnotiformes: Apteronotidae)

The Neotropical ghost knifefish genus Sternarchogiton is revised on the basis of morphology and pigmentation. A new diagnosis for the genus is provided. Two new deep-channel taxa from the lowland portions of the Amazon basin are described: S. labiatus and S. preto. Sternarchogiton labiatus is diagnosed by the possession of a hard, prominent, three-lobed structure on the lower lips, two rows of teeth on the dentary, a second hypobranchial with a medial bridge, an ossified first basibranchial, and cartilaginous posterior basibranchials. Sternarchogiton preto is diagnosed by black or very dark brown body coloration, five long and conical teeth on the premaxilla, a dentary with one row of conical teeth pointing toward inside of mouth, the fusion of the supracleithrum and posttemporal, and anterior portion of coracoid not reaching anterior edge of cleithrum. A dichotomous key to species of the genus is provided. © 2007 by the American Society of Ichthyologists and Herpetologists