Moenkhausia chlorophthalma is distinguished

from all congeners, except M. petymbuaba and M. plumbea by the presence of large dark blotches on the anterior to central portions of the scales forming the seven dorsalmost longitudinal series (vs. pigmentation absent or, when present, concentrated posteriorly along the border of the scales, and forming a reticulate pattern on the body). Moenkhausia chlorophthalma can be differentiated from both M. petymbuaba and M. plumbea by the possession of a proximal well-delimited black area on the adipose fin (vs. adipose fin with uniformly scattered dark chromatophores), 7 longitudinal rows of large dark blotches (vs. 8-9), 25-28 lateral line scales (vs. 33-36), 4 scales between the lateral line and the dorsal-fin origin (vs. 5), and 7-12 scales covering the anal-fin base (vs. 4-9). Moenkhausia chlorophthalma can be further separated from M. petymbuaba by lacking a conspicuous midlateral dark stripe (vs. presence of conspicuous midlateral dark stripe); and from M. plumbea by having 7 branched pelvic-fin rays (vs. 6-7 in specimens of M. plumbea examined) (Ref. 84462).