The exotic gastropod Clea helena (von dem Busch, 1847) as a predator of freshwater gastropods: a threat to native biota in India?

Abstract

The carnivorous snail Clea (Anentome) helena (von dem Busch, 1847) (Gastropoda: Nassariidae), commonly called as the “assassin snail” is sold worldwide including India for aesthetics and the ability to kill pest snails in aquaria. Assuming invasion as a fair possibility, the predation potential of C. helena on seven native freshwater snails was assessed. The exotic predator consumed all the native snail species provided in the experiment and prey consumption varied with the prey species identity, the prey density and the prey size class. Future colonization and establishment of C. helena in Indian freshwater ecosystems may reduce the abundance of the native gastropod snails, in absence of suitable intervention.