Mauro L. Triques
Apteronotus acidops, new species, is described from the upper Paraná River basin, Brazil. It can be diagnosed from the remaining species of the genus by the following combination of characters: dorsal snout profi le pointed; snout length 46.4 – 63.7 % of head length; oculo-nasal distance 39.2 – 72.1 % of postocular distance; lateral ethmoid with both dorsal and ventral extremities expanded, strongly oblique in orientation; mouth rictus surpassing vertical through anterior eye margin, including its skin folds, in all ages; dorsal head profi le nearly horizontal from a vertical through anus to posterior extremity of occipital bone; absence of mid-dorsal white or clear stripe on head and body anteriorly; chin brown; upper lip clear to a vertical through anterior nostril; transversal unpigmented bar or bars posteriorly on the body absent; fl anks brown, darker dorsally and pectoral fi n hyaline, with chromatophores over rays. Moreover, a key for the apteronotid species from the upper rio Paraná is provided.
Quelle: Vertebrate Zoology 61 (3) 2011, 299 – 306 (pdf, öffentlich)