Leucos basak is distinguished from other congeners by the following characters: moderate size, usually 12.0-14.0 cm SL; lack of a mid-lateral band; body uniformly silvery in life; peritoneal membrane black; usually 36-38 pored scales on lateral line (vs. 38-43 in the other congeners). It differs from Leucos aula by the absence of lateral band and black peritoneal membrane (vs. silvery in L. aula); from L. panosi and L. ylikiensis mainly by having usually 9-10 gill rakes (vs. 18-20 in L. ylikiensis and 13-14 in L. panosi). Leucos basak is most closely related to L. albus based on molecular analyses but differs from this species by having 36-38 scales on lateral line (vs. usually 41-42 in L. albus); 9 branched dorsal rays (vs. 8 in L. albus); and blackish peritoneal membrane (vs. nearly silvery in L. albus) (Ref. 96829).