Marine fish with cartilaginous skeleton. Five gill opening. Short and rounded head. Eyes large, oval, green. Mouth full of fleshy, bloody lips; Denture with small and sharp upper teeth, and lower serrated edge widths. Two dorsal fins, without anal fin and with pelvic fins very late. Extremely wide caudal fin, with only slightly differentiated lower lobe. No spines in front of the dorsal fins. Very strong and grainy skin, like sandpaper. Blackish-brown uniform color. Fins with a thin white border. Up to 2 m in length.