Francisco Javier Zamora-Camacho and Pedro Aragón
Tadpoles use their tails to swim, which is their primary defence against predators. However, predators often fail in their attack attempts, tearing only a part of the tail of fleeing tadpoles. Although tadpoles can survive these failed attacks, partial tail loss commonly reduces swimming speed, and therefore their ability to escape predators in subsequent encounters. Nevertheless, little is known about the potential effects of partial tail loss on locomotion after metamorphosis. Tadpoles resorb their tails in the latter stages of metamorphosis. It has been previously shown that toadlets resulting from tadpoles that had partly lost their tails finish metamorphosis in a poorer body condition. This finding could suggest that the material contained in the tail is important in building the toadlet body, and thus tadpoles that have partly lost their tails have less tail material and result in thinner toadlets.
Following this rationale, we tested the hypothesis that the loss of tail material in tadpoles will also result in shorter-limbed toadlets. In such a case, jumping ability of resulting toadlets should be negatively affected, because jumping ability in toads and frogs is greater as hindlimb length increases. We tested these hypotheses in tadpoles of western spadefoot toads (Pelobates cultripes), and found that toadlets resulting from tail-clipped tadpoles had shorter hindlimbs and, consequently, jumped shorter distances. Therefore, partial tail loss in tadpoles, a common outcome of failed predation attempts, has negative effects on locomotion that persist after metamorphosis, which might compromise the ability of both tadpoles and toadlets to survive further predator attacks.