Growth rate plasticity in larval Northern Leopard frogs

Compensatory growth is rapid growth after a period of growth depression. We studied growth rates of Northern Leopard frog tadpoles (Lithobates pipiens) after a period of growth depression induced by predation or competition. I predicted that tadpoles in treatments with high competition would have long guts that facilitated compensatory growth. I also predicted that tadpoles exposed to predation would have short guts that would prevent compensatory growth. Tadpoles were reared at low and high density in 410 L mesocosms with and without a caged predator. Each treatment was replicated 5 times. When tadpoles reached 4cm in length, 3 tadpoles from each treatment were transferred to a new mesocosm with ad libitum food and no predators. They were allowed to grow for one week. Initially, tadpoles reared without predators grew faster, but no tadpoles showed signed of compensatory growth post transfer. Unexpectedly, high competition tadpoles had a greater intake than low competition tadpoles, but grew more slowly. Tadpoles reared without predators had longer tails than those reared with predators, but there was no difference in gut length between any treatments. Cold temperatures during the first weeks of the study could have affected the results. Nonetheless, larvae did exhibit a high degree of growth-rate plasticity