Bryconamericus

1. Greatest body depth contained 2.7 to 2.9 times in standard lenght; teeth in the outer premaxillary series forming a regular arch.................................. B. aff. iheringii

1’. Greatest body depth contained 3.3 to 4.2 times in standard lenght; teeth in the outer premaxillary series irregularly arranged............................................................. 2

2. Distal portion of caudal-fin lobes black; dorsal and anal fins completely hyaline; mature males with bony hooks on the anal- and pelvic-fin rays; 2-3 maxillary teeth ................. ............................................................................... B. exodon

2’. Distal portion of caudal-fin lobes hyaline; middle portion of the dorsal- and anal-fin rays dusky; bony hooks always absent on the anal- and pelvic-fin rays; 2-5 maxillary teeth ...................................................... B. turiuba