The Potential of the Invasive SnailPomacea canaliculataas a Predator of Various Life-Stages of Five Species of Freshwater Snails

Abstract

The invasive apple snail Pomacea canaliculata is known as an omnivorous species, but there are only few reports of its predation. This study examined the potential of this snail as a predator of common freshwater snails in southern China. Laboratory experiments were conducted to quantify the damage of the apple snail to both early stages (eggs and/or neonates) and adults of five species of freshwater snails (Austropeplea ollula, Biomphalaria straminea, Melanoides tuberculata, Physa acuta, Sinotaia quadrata). The apple snail caused significant mortality to all of the early stages of the five snails, as well as adults of the pulmonates A. ollula, B. straminea and P. acuta, but did not consume adults of the prosobranchs M. tuberculata and S. quadrata. Such differential survival of the prey might be explained by differences in shell hardness and structure, as the adult prosobranchs were well protected by a hard shell and an operculum, whereas the pulmonates had a relatively fragile shell and lacked an operculum. The apple snail was unable to detect its prey from a distance, but it crawled quickly, which could create opportunities for direct contact with potential prey. Apple snails may therefore influence invaded ecosystems through predation on other freshwater snails.