Zygogaster, EIGENMANN 1913

CF. ZYGOGASTER EIGENMANN 1913

Type species: Zygogaster filiferus Eigenmann, 1913 (not analysed herein).

Because the type species of Zygogaster was not analysed, the putative generic assignment of the included species may vary in the future. The species herein analysed share the presence of an oval humeral spot (which is absent in Astyanax filiferus ) and the following morphological synapomorphies: presence of a posteriorly oriented epioccipital spine (66:0), five or more cusps on outer premaxillary teeth (193:1), longitudinal ridge on medial surface of opercle reaching 60% or more of its length (254:0), presence of denticles on entire surface of the gill rakers (301:1) and presence of 25 or more gill filaments attached to leading edge of first ceratobranchial (304:1).

Zygogaster was proposed as a genus by Eigenmann (1913) and shortly after considered a subgenus of Astyanax ( Eigenmann, 1917) View in CoL . This subgenus included five species [ Astyanax atratoensis ( Eigenmann, 1907) View in CoL , A. caucanus (Steindachner, 1879) View in CoL , A. filiferus View in CoL , A. magdalenae Eigenmann & Henn, 1916 View in CoL and A. stilbe (Cope, 1870) View in CoL ]. We find three of these species to form a clade that does not include the type species of Astyanax View in CoL . Zygogaster is, thus, a candidate genus to be resurrected. However, we do not have enough evidence to do so, because we could not analyse the type species of the genus ( Zygogaster filiferus View in CoL ).