Most poisonous New World snakes belong to the pit viper family; these include the copperhead, water moccasin, rattlesnake, fer-de-lance, and bushmaster. Venomous Old World snakes are the true vipers, including the adder and the asp, and members of the cobra family, including the mamba of Africa and the krait of Asia. The poisonous coral snakes of the New World also belong to this family. The venomous sea snakes inhabit tropical oceans.