Antipredator behaviour in response to single or combined predator cues in the apple snail Pomacea canaliculata

Abstract

The documentation of antipredator behaviour associated with different risk levels (threat-sensitive predator avoidance), different predators (predator-specific avoidance) or combined predators (multiple predator avoidance) in freshwater caenogastropods is limited. We studied the antipredator behaviour of predator-naive hatchlings of the invasive apple snail Pomacea canaliculata to chemical cues from the common carp (Cyprinus carpio), Reeve's turtle (Mauremys reevesii) and crushed conspecifics in three laboratory experiments. First, we tested the snails' responses of crawling out of the water and self-burial in the sand to odour from a single nonfeeding predator or crushed conspecifics. A greater proportion of snails responded to odour from crushed conspecifics than to turtle or carp odours. Second, we studied the snails' responses to cues simulating a single feeding predator. When combined with cues from crushed conspecifics, snails tended to bury themselves in the sand in response to the turtle odour whereas they tended to crawl above the waterline in response to the carp odour. Third, we compared the snails' responses to single or combined predator cues. In the presence of cues from crushed conspecifics, the snails' responses to the combined odours from turtle and carp were more similar to the responses associated with the carp odour than to those associated with the turtle odour. Overall, these experiments indicate that P. canaliculata hatchlings show fine-tuned innate antipredator behaviour.