Gymnocranius frenatus

Gymnocranius elongatus differs in having no blue lines on snout and cheek (vs. 3 or 4 oblique, wavy blue lines present) and a deeply forked caudal fin (vs. moderately forked).

Gymnocranius grandoculis differs in having a maximum length of up to 80 cm TL, commonly 50 cm TL (vs. 35 cm TL); wavy blue lines on snout and cheek horizontal only (vs. wavy blue lines on snout and cheek oblique and snout with prominent blue-edged yellow band from front of eye to above upper lip, encompassing nostrils) and specimens <25 cm SL frequently with dark bar below eye and 5 or 6 irregular dark bars on side, specimens >25 cm SL silvery (vs. body silvery with about 5–7 narrow, irregular dark bars on sides).

Gymnocranius griseus differs in having no blue markings on snout and cheek (vs. 3 or 4 oblique, wavy blue lines on snout and cheek).

Gymnocranius microdon differs in having vertically elongate blue spots often on snout and cheek (vs. 3 or 4 oblique, wavy blue lines on snout and cheek).

Gymnocranius obesus differs in having no blue markings on snout or cheek (vs. 3 or 4 oblique, wavy blue lines on snout and cheek).

Gymnocranius satoi differs in having blue speckles on snout and cheek (vs. 3 or 4 oblique, wavy blue lines present); body silvery (vs. silvery grey with 5–7 narrow, irregular dark bars) and inside edges of caudal-fin lobes convex (vs. straight).