Sub-rhomboid in shape with a short rostrum and rounded wing-tips. Upper surface almost smooth in young, but prickly in large specimens, except for bare centers of pectoral fins and hind part of disc, underside nearly smooth; orbital thorns separate, a regular row of 20-50 usually persistent thorns from nape to first dorsal fin; with 1-2 thorns between dorsal fins; 2 equal-sized dorsal fins at end of tail. Brownish dorsally with numerous small dark spots which do not reach the margin of the disc, frequently with a concentration of dark spots forming a ring around a pale centre on hind part of each pectoral fin, underside white (Ref. 3167).