Astyanax salvatoris is distinguished from other congeners in Oaxaca by following characters: anal-fin rays 20-22 (vs. 21-26); total gill rakers, mean 17 (vs. mean 22 or more in A. finitimus); anterior fontanel sharp-tipped (vs. blunt), long (vs. shorter in A. finitimus); in dorsal view, supraoccipital short, wide-based (vs. long, narrow-based in A. aeneus); 4 maxillary teeth, 2 larger followed by 2 smaller (vs. 1-3, all about same size); epibranchial III distal segment straight (vs. curved in A. finitimus); preopercular ventral rim, convex (vs. straight in A. aeneus); and predorsal elements irregularly expanded (Ref. 118583).