Invasive apple snails (Pomacea canaliculata) are predators of amphibians in South China

Invasive species are one of the most serious threats to amphibian populations. We investigated the effects of two invasive (Pomacea canaliculata and Physella acuta) and one native (Radix sp.) snail species on five species of wetland-breeding frogs in Hong Kong. We quantified embryonic survivorship and determined whether particular attributes of amphibian egg masses influenced consumption by snails. P. canaliculata preyed on four of the species, consuming > 90 % of eggs of Microhyla fissipes and Fejervarya limnocharis, nearly 70 % of eggs of Kaloula pulchra, approximately 40 % of eggs of Duttaphrynus melanostictus, but no eggs of Polypedates megacephalus. P. acuta and Radix sp. consumed only the eggs of K. pulchra, but those eggs were probably non-viable. This study shows that P. canaliculata, which occurs at high densities in tropical East Asia, may be an important predator of amphibian eggs. Future research should evaluate their effects on amphibian populations, community structure, and food web dynamics.