Melanotaenia albimarginata is distinguished by the following combination of characters: V or VI-I,11 or 12 dorsal-fin rays; I,19-22 anal-fin rays; 14-15 pectoral-fin rays; 35-36 scales on lateral line, 16-18 predorsal scales; 12-19 cheek scales; 16-18 total gill rakers on first arch; greatest body depth of adult male 36.2 % SL; least depth of caudal peduncle 9.6-10.9 % SL; color in life dappled grey on upper side, dark grey midlateral stripe (1-2 scales wide) with equally broad yellow stripe immediately below; dorsal and anal fins with greyish membranes and whitish to pale yellow fin rays; caudal semitranslucent grey with prominent white marking at tip of upper and lower lobes (Ref. 110723).