This species is distinguished from all Sundaic congeners in having the following unique characters: premaxillary toothband is approximately half exposed when the mouth is closed; eye diameter 7-9% HL; interorbital distance 28-33% HL; head width 19.4-22.3% SL; in the thoracic adhesive apparatus, no anteromedial striae but with medial pit; pectoral-fin spine length 13.6-17.9% SL; posterior margin of dorsal-fin spine smooth; margin of dorsal fin concave; prepelvic length 49.1-54.6% SL; preanal length 65.7-72.3% SL; body depth at anus 15.4-19.0% SL; adipose-fin base length 13.6-18.0% SL; caudal peduncle depth 8.0-11.4% SL (1.4-2.1 times in its length; 1.3-2.0 times in body depth at dorsal-fin origin); caudal peduncle length 15.5-18.2% SL; post-adipose distance 14.6-17.6% SL; caudal-fin with length 20.1-27.0% SL, the broad lobes lacking prominent dark longitudinal stripes running through each lobe (Ref. 128699).

Description: It differs from G. robustus, the only other congener known from Java, in having (vs. lacking) a medial pit in the thoracic adhesive apparatus, a convex (vs. straight) dorsoposterior margin of the adipose fin, caudal peduncle 8.0-11.4% SL (vs. 6.6-8.3), shorter caudal fin 20.1-27.0% SL (vs. 26.5-30.4) with broader lobes lacking (vs. having) prominent dark longitudinal stripes running through each lobe and the difference in the caudal peduncle depth more marked when compared to the body depth at dorsal-fin origin, caudal peduncle depth 1.3-2.0 times in body depth at dorsal-fin origin (vs. 2.2-2.8) (Ref. 128699).