(Family): Dorsal fin absent. Tail exceedingly long, its length 1.5〜2.0 times of preanal length. (Genus): No large thorns along midline of back and around eye. Tail length 1.5 times of preanal length. Rostral cartilage short and slender, not extending to tip of snout. (Species): Upper surface with minute denticles but sparsely present; lower surface with thorns but scattered sparsely. Thorns of middle of disc and tail weak and irregularly spaced. Secondary sexual characters distinct; mature males with several rows of strong alar thorns; outer margin of disc beside eye deeply concave; mouth strongly arched. Body pale brown with a number of dark bars on tail.
Distribution:
Caribbean Sea to Brazil.
Remarks:
G. furvescens, closely similar species, has shorter snout, preocular length 13% of DW (20% in the present specimens); and wider interbranchial region, distance between first gill-openings 22% of DW (19% in the present specimens). (Uyeno and Miyake)