Found on the continental shelf, especially abundant off river mouths on muddy bottoms. Salinity: 35-36 ppt. Oxygen: 3-4 ppm. Feeds on small bottom and littoral organisms like crustaceans, bony fishes, octopi and sponges. Viviparous (Ref. 50449), with 7 young in a litter (Ref. 244). Dental sexual dimorphism is manifested by males having greatly enlarged anterior teeth. Utilized fresh, smoked or dried salted for human consumption, skin for leather.