Density Mediates the Predator-Induced Growth and Metamorphic Plasticity of Chinhai Spiny Newt Larvae

Simple Summary In this study, we investigated how predators and conspecific density impact the growth of Chinhai spiny newt larvae. Using a two-factor experimental design, we manipulated both factors to explore their independent and interactive effects on larval development. Our findings demonstrate that both high and low conspecific densities constrain larval growth, while predators also limit growth. Interestingly, high conspecific density restricts predator-induced growth plasticity without interacting effects. This study provides valuable insights into the complex interplay between environmental factors and larval development in endangered Chinhai spiny newts. Understanding these dynamics is crucial for informing conservation strategies aimed at protecting this vulnerable species. Predators significantly influence amphibian larval development. Predator-induced plasticity is often studied independently from conspecific density effects, but these environmental factors may interact. We conducted two-factor factorial experimental design to manipulate conspecific density and predator cues, aiming to investigate the independently or interactive impacts of these two factors on the development of Chinhai spiny newt larvae (Echinotriton chinhaiensis). Our findings reveal that both high and low conspecific densities constrain spiny newt larval growth and predators also limit growth. Interestingly, high conspecific density restricts predator-induced growth plasticity without interacting effects. Only lower density groups exhibit slower growth responses to predators. Our study investigates how density mediates predator-induced plasticity in the endangered Chinhai spiny newt larvae, providing insights into their intricate life history. These results contribute to the understanding of predator-induced plasticity in amphibians and provide insights into the adaptive strategies of endangered species like Chinhai spiny newt. Such knowledge informs the development of effective conservation strategies for their protection.