The body is oblong, elongated (depth 36-45% of SL in adults), robust, and compressed. Cheeks lack longitudinal grooves, but there’s a distinct groove before the eye and below the nostril. The small mouth opens at the front with powerful jaws, featuring 8 heavy, unevenly notched teeth on the upper and lower jaws. The gill opening is a short slit on the side before the pectoral base. The dorsal fin has III spines and 23-25 rays, while the anal fin has 20-22 rays. Pectoral rays number 13-15. The soft dorsal and anal fins are long and curved, with anterior rays much longer than posterior rays. The dorsal, anal, and pectoral fins have mostly branched rays. The tail base is compressed without spines, tubercles, or ridges, and the caudal fin is double concave, rounded in juveniles. Pelvic fins are externally reduced to 4 pairs of large scales encasing the end of the pelvis. The skin is thick, leathery, very rough, with regularly arranged diagonal scale plates. The snout lacks scales, and there’s no patch of enlarged scales behind the gill opening. The coloration is blue-grey to nearly black, often covered with small white spots. It grows to a size of 50 cm.