Habitat size changes morphological traits of Physalaemus albonotatus tadpoles

Abstract

Desiccation exposes tadpoles to a decrease in habitat size due to a reduction in water depth and surface area. We tested the effect of surface area and water depth on growth and development of tadpoles of Physalaemus albonotatus and whether habitat size effects are constant over the larval period. We performed a 2 × 2 factorial design: two water depths and two surface areas. We measured tadpoles at 15 and 30 days after starting the experiment, and recorded weight and time to metamorphosis. Our results indicate that habitat size influences the morphology, growth, and development of tadpoles and that the response changes during development. At 15 days, tadpoles reared in shallow water had reduced their morphological variables and developmental stage, whereas tadpoles reared in enclosures with different surface areas showed no differences. At 30 days, tadpoles reared in enclosures with small surface areas had increased their body length, body height, and developmental stage, whereas tadpoles reared in different water depths showed no differences. Tadpoles reared in small surface areas reached metamorphosis earlier than tadpoles reared in large surface areas. The results suggest that during ontogeny the surface area and water depth had different influence in the phenotypic plasticity of tadpoles.