Guo Jing, Martín Pablo R, Zhang Chunxia, Zhang Jia-En
Department of Ecology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, China.
Laboratorio de Ecología, INBIOSUR (UNS/CONICET), Departmento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur, Bahía Blanca, Argentina.
PLoS One. 2017 Nov 14;12(11):e0187747. doi: 10.1371/journal.pone.0187747. eCollection 2017.
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 a reduction in food intake. Adult females exhibited a greater reduction in growth under predation risk than males, which likely resulted in part from the high reproductive investment of females in egg laying. These results indicate that P. canaliculata snails under predation risk face a trade-off between predator avoidance and growth and reproduction, where the lethal effect of predation risk is linked to the size of the prey.
入侵物种在被捕食风险下的行为已得到广泛研究，但它们的生长和繁殖反应却很少被调查。我们用入侵淡水螺福寿螺的幼体和成体进行了实验，并观察了它们在面对来自笼养捕食者（华丽滑龟）的捕食风险时生长和繁殖的变化。与对照组（无风险）相比，福寿螺在有捕食者和受伤同种个体存在时产卵更早，不过15天后每个雌螺产下的卵块总数超过了对照组。在捕食风险下，卵的孵化成功率显著降低，孵化期也显著延长；然而，螺的产卵高度并未受到影响。在幼螺中检测到了捕食风险的致死效应，但成螺中未检测到。捕食风险下福寿螺幼体的生长受到抑制，这可能是由于食物摄入量减少所致。成年雌螺在捕食风险下的生长下降幅度比雄螺更大，这可能部分是由于雌螺在产卵方面的高繁殖投入。这些结果表明，处于捕食风险下的福寿螺在躲避捕食者与生长和繁殖之间面临权衡，其中捕食风险的致死效应与猎物的大小有关。
