Ancistrodon

Ancistrodon 

(also Agkistrodon), a genus of poisonous reptiles of the family Crotalidae (rattlesnakes). The top of the head is covered with large symmetrical plates, and the body scales have a rugged surface; there is no rattle on the tail. The snakes measure as much as 1 m in length and have mottled markings. The genus embraces 13 species, of which ten are found in Asia (one of these also in southeastern Europe) and three in North and Central America.

Representatives of the genus are mainly crepuscular and nocturnal. They live chiefly in dry places, but some have strong aquatic habits, for example, the water moccasin (A. piscivorus), a North American species. The snakes are ovoviviparous. They feed on frogs, rodents, and lizards, as well as invertebrates. The USSR has two species: A. blomhoffi, which inhabits southeastern parts of the Far East, and A. halys, found from the southern Trans-Volga Region and southeastern Azerbaijan to the southeastern borders of the USSR. The bite of the snakes is painful to humans, but recovery is usually complete in five to seven days.