Plastic patterns in larval development of Endangered endemic Atelognathus patagonicus: implications for conservation strategies

Abstract

The Patagonia frog Atelognathus patagonicus (Anura, Ceratophryidae) is endemic to north-western Patagonia where it inhabits permanent and temporary water bodies in a system of endorheic ponds on the basaltic plateau in and around Laguna Blanca National Park, north- western Patagonia, Argentina. This Endangered species is emblematic of the decline and extinc- tion of amphibian populations as a result of the introduction of fish to Laguna Blanca. Therefore, the aims of this study were to determine the patterns of larval development in ponds with different hydro periods and to evaluate the occurrence of different developmental strategies and their impli- cations for conservation management. In permanent ponds, A. patagonicus tadpoles showed a double strategy, with the presence of both seasonal (short larval period; metamorphs in the same growing season) and overwintering tadpoles (undergoing metamorphosis the following spring). In temporary ponds, desiccation seems to exert great pressure, with accelerated larval development, resulting in short larval periods. Atelognathus patagonicus showed plasticity in the length of larval development, adjusting to the different hydroperiods observed in these wetlands. As a result of this dual strategy, overwintering tadpoles in permanent ponds are larger than seasonal tadpoles. This notable plasticity in developmental strategy enables this species to colonize widely varying environments. These results highlight the importance of preserving a variety of wetlands, includ- ing both temporary and permanent ponds, to allow this species to continue to breed and develop in the face of current and potential anthropogenic disturbance, in particular that caused by the activity of local native pastoralists.