A cartilaginous fish with placoid scales, a short, rounded and blunt snout, and small eyes. 12-14 teeth on each side of upper jaw and 12-13 on each side of lower jaw. Teeth serrated, large, broad and triangular near jaw symphysis, but slightly oblique and more concave near mouth corners. No interdorsal ridge. Upper precaudal pit well-developed, but lower one weak. Males with claspers. A marine coastal and coral fish, but enters brackish and freshwaters of rivers and penetrates far up rivers, as far as 125 km up, in summer. Maximum age 20 years and total length 3.5 m, but up to 2 m in Iran rivers. Females larger than males. Maturity at age 10-15 years, in males attained at 160-230 cm, and in females at 180-230 cm. Viviparous and females may contain up to 13 embryos. Gestation period 10-11 months and birth size 56-81 cm total length. Carries embryos through out the year with a peak in late spring and early summer. Birth takes place in estuaries and river mouths. Food include fishes, large crustaceans, molluscs, cephalopods, sea urchins, turtles, sea birds and mammals.