STERNOPYGUS Müller, Troschel, 1846 (8 species) Sternopygus Müller, Troschel, in Müller, 1846: 194 (footnote 2). Type species: Gymnotus aequilabiatus Humboldt, 1805. Type by subsequent designation, herein. Gender: masculine. Gymnotes Gill, 1864: 152. Type species: Gymnotus aequilabiatus Humb [oldt, 1805]. Type by monotypy. Gender: masculine. Hildatia Fernández-Yépez, 1968: [3]. Type species: Hildatia brasiliensis Fernández-Yépez, 1968. Type by original designation. Gender: feminine. Remarks: Sternopygus appeared first with reference to “ Gymnotus macrurus Bl. [= Bloch (1786, 59, pl. 157, fig. 2)] und 4 andere Arten.” That reference to Gymnotus macrurus Bl. appears to be the basis for a type species designation, except that the name was not binomial and, instead, was the beginning of “ Gymnotus macrourus maxilla superior longiore,” a diagnosis for the species listed as Gymnotus carapo in both the text and figure caption. Subsequent authors reported that the type species is Gymnotus macrurus Bloch, Schneider, 1801, but Müller referenced that publication as Bl. Schn., as was done for Gymnotus rostratus in the paragraph on Rhamphichthys in the same footnote. As no available species names were listed in the account of Sternopygus, it is necessary to select a type species from among the first listed nominal species in a subsequent account of the genus, following Code Art. 67.2.2 (ICZN, 1999). Müller, Troschel (1848) was the next publication that treated Sternopygus as a valid name. Therein, four nominal species were listed as being included in the genus: S. virescens (Valenciennes, 1836), S. lineatus Müller, Troschel, 1848, Sternopygus macrurus Müller, Troschel, 1848, and Gymnotus aequilabiatus Humboldt, 1805. No designations from among those names has been found. Instead, Gymnonotus macrurus Bloch, Schneider, 1801, which was listed first in the account of Sternopygus in Müller, Troschel (1849), has been widely reported as the type species, first by Eigenmann (1910). However, as Gymnonotus macrurus Bloch, Schneider was not included in the account of Sternopygus in Müller, Troschel (1848), it cannot be validly selected as the type species. Inasmuch as two of the names available for selection as type species are currently assigned to the genus Eigenmannia, it is necessary to select a type that will stabilize Sternopygus as well as not disrupt the validity of Eigenmannia. To accomplish those goals, we select herein Gymnotus aequilabiatus Humboldt, 1805, as type of Sternopygus. Phylogeny: Hulen et al. (2005). Checklist: Crampton, Hulen, Albert (2004b). Key: Albert, Fink (1996); Hulen et al. (2005).

Published as part of Carl J. Ferraris, Jr., Santana, Carlos David de & Vari, Richard P., 2017, Checklist of Gymnotiformes (Osteichthyes: Ostariophysi) and catalogue of primary types, pp. e 160067 in Neotropical Ichthyology 15 (1) on pages e160067-160067, DOI: 10.1590/1982-0224-20160067, http://zenodo.org/record/20087294