Does carnivory pay off? Experiments on the effects of different types of diet on growth and development of Bufo bufo (Linnaeus, 1758) tadpoles and carry-over effects after metamorphosis
Natural diets of anuran larvae vary widely in their relative amounts of nutrients. The proportion of these ingested nutrients has significant influence on larval and post-metamorphic performance. Here, we use the Common Toad to address the role of diet (exclusively carnivore, exclusively vegetarian and mixed) on growth and development of tadpoles and short-term carry-over effects on post-metamorphic animals. Larvae fed on an exclusively vegetarian diet performed better (faster growth and
... r growth and development) than larvae fed on exclusively carnivore and mixed diets. Larvae fed on the exclusively carnivore diet had the lowest performance. Regarding the carry-over effects of larval diets, although the body condition indices of the toadlets were similar in all treatments, there was a major difference in the survival rate. While toadlets, originating from larvae fed on a vegetarian diet, were more successful and had the lowest mortality, those fed on a carnivore diet had the highest mortality level. Our results suggest that a plant-based diet may contain all the necessary nutrients needed by Bufobufo larvae. Furthermore, a diet based exclusively on food of animal origin might be detrimental for the larval performance and could have significant carry-over effects on the post-metamorphic animal.