This species is distinguished from its congeners, except M. grandisquamis, M. tergimacula, M. xinguensis, by having a single humeral spot, with a silvery lateral stripe, no dark line at the base of the anal-fin rays, no caudal lobule mark, dorsal fin hyaline, with 5 series of scales above lateral line and 4 series of scales below lateral line; differs from M. tergimacula by the absence of a dark spot anteriorly to the dorsal-fin origin; differs from M. xinguensis by the scales showing upward and downward bent radii (vs. scales with straight radii); differs from M. grandisquamis by its larger humeral spot, located over the third to fifth or fourth to sixth lateral-line scales and extending vertically over three or four horizontal scale rows above the lateral line (vs. a smaller humeral spot, located over second to third or third to fourth scale of the series immediately above the lateral line); also differs by having 4 or 5 cusps on the second tooth of the inner row of the premaxilla (vs. eight, seven, occasionally six cusps on the second tooth of the inner row of the premaxilla in M. grandisquamis) (Ref. 112434).