Gymnocranius microdon

Gymnocranius elongatus differs in having a deeply forked caudal fin, the median rays shorter than eye diameter (vs. moderately forked caudal fin, the median rays longer than eye diameter) and lower edge of eye level with snout tip to middle of caudal-fin fork (vs. lower edge of eye above line from snout tip to middle of caudal-fin fork).

Gymnocranius frenatus differs in having oblique, wavy blue lines on snout and cheek (vs. vertically elongate blue spots often on snout and cheek) and inner edge of caudal-fin lobes convex (vs. straight).

Gymnocranius grandoculis differs in having horizontal, wavy blue lines on snout and cheek for specimens >20 cm TL, or a dark bar under eyes and 5 or 6 irregular dark bars on sides for specimens <20 cm SL (vs. vertically elongate blue spots on snout and cheek, body silvery) and body depth 2.4–2.5 times in standard length (vs. 2.5–3).

Gymnocranius euanus differs in having 4½ scale rows between lateral line and base of middle dorsal-fin spines (vs. 5½).

 Gymnocranius griseus differs in having no markings on snout and cheek (vs. vertically elongate blue spots on snout and cheek).

Gymnocranius satoi differs in having blue speckles on snout and cheek (vs. vertically elongate blue spots on snout and cheek) and caudal-fin tips rounded (vs. pointed). 

Gymnocranius obesus differs in having no markings on snout and cheek (vs. vertically elongate blue spots on snout and cheek).