Predation risk affects growth and reproduction of an invasive snail and its lethal effect depends on prey size

The behavior of invasive species under predation risk has been studied extensively, but their growth and reproductive responses have rarely been investigated. We conducted experiments with juveniles and adults of the invasive freshwater snail Pomacea canaliculata, and we observed changes in growth and reproduction in response to predation risk from a caged predator (Trachemys scripta elegans). P. canaliculata produced eggs earlier in the presence of predators and injured conspecifics compared with the control group (no risk), although the total number of egg masses laid by per female was exceeded by that of the controls after 15 days. Egg hatching success noticeably decreased under predation risk, and the incubation period was significantly prolonged; however, the oviposition height of the snails was not affected. A lethal effect of predation risk was detected in juvenile snails but not in adults. The growth of juvenile P. canaliculata was inhibited under predation risk, probably due to...捕食风险下入侵物种的行为已得到广泛研究，但针对其生长与繁殖响应的相关探究却较为少见。本研究以入侵性淡水螺类福寿螺（Pomacea canaliculata）的幼螺与成螺为实验对象，观测其在笼养捕食者红耳龟（Trachemys scripta elegans）带来的捕食风险下的生长与繁殖变化。与对照组（无捕食风险组）相比，捕食者与受伤同种个体存在时，福寿螺产卵更早，但15天后对照组每雌螺的总产卵块数反超实验组。捕食风险下，福寿螺卵的孵化成功率显著降低，孵化周期明显延长；但福寿螺的产卵高度未受显著影响。研究发现捕食风险对幼螺存在致死效应，但对成螺无此影响。捕食风险下幼龄福寿螺的生长受到抑制，其原因可能为……