Astyanax serratus Garavello & Sampaio 2010

This species can be distinguished from all its congeners from Iguaçu basin by this set of characters: infraorbital 3 narrow and deep but not in contact with preopercle, leaving a naked area approximately 1/5 of height between border and preopercle; premaxillary external series with 2-5, usually 4 tricuspid teeth; non-symphysial teeth in premaxillary internal series pentacuspid; maxillary with 0-4, usually 2 teeth; humeral spot rounded and dark, frequently with a weak and narrow vertical downward prolongation (Ref. 85756).

Dorsal soft rays (total): 8 - 9; Analsoft rays: 16 - 20