Venom of a sea snake is highly potent. A fatal dose of venom from the Beaked sea snake, for an adult human, is only 1.5 mg. An average sized sea snake can produc 10-15 mg of venom.
Even though sting rays skeleton is soft cartilage, they can crush mussel and snail shells in their jaws. They can exert a force equivalent to a 25 kilogram weight sitting on your hand.
