We are what what we eat eats: the effects of prey diet on growth, development, behavior and survival of a secondary consumer

Secondary consumers meet their nutritional needs via their prey and are limited by the dietary resources available for their prey. This is especially relevant in ecosystems which cannot be abandoned, such as in small water bodies. In this work, I studied how urodele larval growth, development and behavior are affected by the diet of their prey. I reared Salamandra salamandra larvae in captivity, feeding them mosquito larvae fed either a plant-based (vegetal treatment) diet, a meat-based (animal treatment) diet or a combined diet (mixed treatment). I measured body size of salamander larvae and metamorphs, locomotor performance, flight initiation distance, and feeding rates of larvae, and time and survival until metamorphosis. The vegetal treatment showed reduced body size, lower foraging rates, and lower survival. Locomotor performance, flight initiation distance, and time to metamorphosis were not affected by treatment. These results highlight how prey diet affects secondary consumers. Thus, the success of a given individual can depend on the productivity of its ecosystem or the income of exogen matter.