This species is distinguished by the following characters: many reddish spots/stripes on a yellow-green or sky-blue body; when alive or freshly-collected, it differs from similar reddish-spotted/lined congeners, G. erythrospilus and G. histrio, by having the following unique coloration: 2 reddish circular spots (rather than linear spots) on pectoral-fin base (vs. reddish markings on pectoral-fin base usually forming vertical bars in G. erythrospilus and G. histrio, except for small specimens of the former with discontinuous bars); reddish spots on ventral surface of head (vs. none); reddish crescent-like bar along bases of pectoral fin rays absent (vs. present); in in alcohol-preserved specimens, all reddish spots are largely or entirely faded, but this species can be readily identified by having its unique squamation, i.e., 3-4 rows of weakly ctenoid and/or cycloid scales on caudal peduncle (vs. no scales or a single row of minute cycloid scales on caudal peduncle in the congeners); with a deep, inflected interopercular-isthmus groove; unsegmented caudal-fin rays, upper with 5-6, lower with 4-6; no distinct dusky spot at dorsoposterior corner of operculum (Ref. 94251).