Genycharax Eigenmann, 1912

The only species described for this genus, Genycharax tarpon Eigenmann, has a general appearance of an Astyanax, but with a clupeoid mouth and elongated and curved teeth. This genus was related with Astyanax and some Characinae by Géry (1977). According to the illustrations of Géry (1977) this species lacks a supraorbital bone, and it would not be included either in the subfamilies Acestrorhynchinae, Agoniatinae, Bryconinae, Cynodontinae, Iguanodectinae or Salmininae, nor in the Bryconops clade. Although this species shares some details of general appearance and the presence of unicuspidate teeth with the Characinae, such a proposed relationship would be speculative and it is maintained herein as incertae sedis.