Brown ghost electric fishes of the Apteronotus leptorhynchus species-group (Ostariophysi, Gymnotiformes); monophyly, major clades, and revision Author Santana, Carlos David De Author Vari, Richard P. text Zoological Journal of the Linnean Society 2013 2013-07-08 168 3 564 596 http://dx.doi.org/10.1111/zoj.12022 journal article 10.1111/zoj.12022 0024-4082 5280846 APTERONOTUS LEPTORHYNCHUS SPECIES- GROUP Diagnosis: Species of the A. leptorhynchus speciesgroup can be readily distinguished from the remaining genera of the Apteronotidae and within Apteronotus via the synapomorphies identified above. The speciesgroup is externally recognizable by the stripe of distinctly paler pigmentation running from the chin along the mid-dorsal region of the head and body to the posterodorsal portion of the body, the pale band encircling the base of the caudal fin, the presence of scales on the dorsal portion of the body, and the possession of posterior dentary teeth two times as large as the anterior teeth on that bone. Distribution: Species of the A. leptorhynchus speciesgroup occur in the Essequibo River system in Guyana , various portions of the Río Orinoco basin, and two coastal Caribbean drainages of northern Venezuela . Trans-Andean species inhabit various drainages of the Lago Maracaibo basin in north-western Venezuela and north-eastern Colombia , the Caribbean versant Rios Atrato, Cauca , and Magdalena of northern Colombia , and Pacific Ocean drainages in Colombia and Panama . Remarks: Albert & Campos-da-Paz (1998) and Albert (2001) , followed by de Santana & Cox-Fernandes (2012) , proposed a slightly more encompassing assemblage than the A. leptorhynchus species-group of this analysis, which additionally incorporated Apteronotus brasiliensis and which they termed the A. brasiliensis species-group. In so far as the data matrices of the analyses Albert & Campos-da-Paz (1998) and Albert (2001) did not include A. brasiliensis , the basis for that assignment is uncertain. More pertinently, information collected in this study failed to support the placement of A. brasiliensis within the A. leptorhynchus species-group and we consequently did not include it here.