Influence of tail injury on the development of Neotropical elegant treefrog tadpoles

Abstract

Anuran larvae in aquatic environments are important prey items for several vertebrate and invertebrate species. Besides avoiding predation, there are some strategies that may reduce the physical damage in those tadpoles that survive the predation attempt. For example, the injured tadpole tail can regrow after a predator bite, but few studies have examined the consequences of such injury. We examined the consequences of three levels of injury to the tail and how this influenced development and feeding behavior of tadpoles of the Neotropical elegant treefrog, Dendropsophus elegans. We collected spawns and kept them in the laboratory until tadpoles reached Gosner’s stages 28 to 35. Then, they were separated in four experimental groups: individuals with tail trimmed in 30, 50 or 70 % of its length, and a control group, with no tail removing. We counted the days until metamorphosis, calculated the Scaled Mass Index (SMI) through weight and length of newly-metamorphosed, and evaluated the feeding frequency to evaluate the influence of tail amputation on them. We found that the time until metamorphosis was positively related to the extent of the amputation, but SMI and feeding behavior were not influenced. As the time to metamorphose is related to the survivorship chances of individuals: i.e., if the aquatic environment is with high density of predators, it would be advantageous to rapidly metamorphose out of the water. However, tail injury delays the metamorphose process, which could influence the survival of the individual.