Leucos aula is distinguished from all congeners by having a middle lateral band and a smaller head length, which in fish of comparable size is less than 4.5 times in the SL, except L.

panosi, and more than 4.0 times in the others species. It further differs by having 12 modal scales around caudal peduncle (vs. 14) (Ref. 96829). It can be diagnosed from its congeners in Apennine Peninsula by having the following characters: dorsal and anal fins with 9½ branched rays; 36-42 (usually 38-39) scales along lateral line; mouth subterminal; pelvic, pectoral and anal fins greyish; eye red in life; conspicuous dark brown midlateral stripe from eye to caudal fin base (Ref. 59043).