The effect of rattlesnake venom on digestion of prey

Abstract

Rattlesnake venom injected into live mice before they were swallowed by non-venomous snakes speeded the process of digestion. This effect of venom was more pronounced when digestion was tested at 15°C than at 25°C. The proteolytic activity of viperid venom appears to facilitate the entry of a snake's stomach secretions into the prey's body cavity, inhibiting bacterial activity and thereby reducing the risk of prey putrefying before it can be digested. This effect would be particularly valuable for snakes that eat very large prey in relation to their own body size or that normally experience low body temperatures after feeding. Viperid snakes comprise a disproportionately large fraction of the total snake fauna at high altitudes in North America and Africa. Proteolytic venom appears to be one of a group of characters that permit viperid snakes to swallow and digest large prey. A digestive function of venom probably appeared at an early stage in the evolution of vipers.