Abstract

Intraspecific competition during the larval stage has important consequences on growth and development resulting in fitness loss at higher densities in many anuran species. Larvae of Crinia georgiana can complete metamorphosis without feeding, which may make the effects of intraspecific competition potentially less significant in this species. The aim of this experiment was to determine if intraspecific competition occurs and results in fitness loss in larvae of C. georgiana. Larvae were raised at high and low densities in mesocosms in the laboratory that simulated natural ponds in the field. Offspring at higher densities metamorphosed at significantly smaller sizes and suffered higher mortality rates than larvae in the low density treatment. Despite this species possessing an egg with a large yolk content in comparison to most anuran species with exotrophic larvae, and having the ability to complete metamorphosis without feeding, intraspecific competition results in important density dependent fitness loss in larvae of C. georgiana when food resources are present.