This species is distinguished from its congeners mainly by the following set of characters: a faint proboscis on the snout, the transverse lobe and lateral surface of snout covered with several unicuspid tubercles; chest and belly covered by scales; branched dorsal-fin rays 7½-8½, branched anal-fin rays 4½; lateral-line scales 39-42; predorsal scales 13-14; circumpeduncular scale rows 12-13; body depth 13.5-17.6% of standard length, caudal-peduncle depth 8.8-11.0% of SL, distance from anus to anal fin 47-56% of pelvic-anal distance; it differs further from G. kempi by having fewer branched anal-fin rays, a shallower body and a more slender caudal peduncle (Ref. 119421).