Diagnosis: head rather rectangular in dorsal outline; snout broadly rounded; frontal fontanelle long and narrow (`knife-shaped'); occipital fontanelle oval-shaped (Ref. 248). "Dermosphenotic" and supraorbital bones fused (Ref. 248), closing up early in the ontogenetic process (Ref. 57129). Pectoral spine slightly curved, showing strong downward pointed serrations on its inner side and relatively small downward pointed serrations on its outer side; openings of secondary canals of lateral line appear as irregular white spots on body (Ref. 248). 43-53 anal fin rays, 57-68 dorsal fin rays (Ref. 57129).

Coloration: live fish: olivaceous-brown on back, olivaceous on sides and whitish on belly (Ref. 57129). Preserved specimens: dark brown on back and sides, belly pale brown; several specimens have a yellowish spot at pelvic-fin bases; caudal fin with a few alternating dark and light vertical bars; dorsal and anal fins sometimes light-edged (Ref. 57129).