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

Me Cuello,Mt Bello,Ca Úbeda,Mg Perotti

doi:10.3354/esr00550

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.

Highlights

The life histories of species that exploit different habitats vary widely
Permanent ponds are more stable environments in terms of hydroperiod duration, and most tadpoles can remain in these ponds for a long time until they reach the optimum size for metamorphosis (Wilbur & Collins 1973), suggesting that temperature may be sufficiently low to make overwintering of larvae obligatory (Berven et al 1979, Collins 1979, Collins & Lewis 1979, Smith-Gill & Berven 1979)
Cuello et al.: Developmental patterns of Endangered Atelognathus patagonicus lands that differed in hydroperiod: Batea Pond and Verde Pond, both located in Laguna Blanca National Park, Neuquén Province, Argentina

Summary

Introduction

The life histories of species that exploit different habitats vary widely. Amphibians use a variety of aquatic habitats, ranging from permanent to ephemeral bodies of water (Werner & McPeek 1994). Amphibians that use temporary environments have life cycles that are synchronized to the pattern of filling and desiccation of the pond (Griffiths 1997), and their larval development period may vary according to how long the water remains in the pond (Wilbur & Collins 1973). This is true of the larvae of some anuran species which, in response to pond drying, have accelerated development rates at the expense of growth in order to ensure metamorphosis to the terrestrial phase before all Endang Species Res 23: 83–92, 2014 the water is lost (Crump 1989, Newman 1989, Laurila & Kujasalo 1999, Perotti et al 2011). The time over which larvae complete their growth and development may range from a few months to a year or even longer (Wilbur & Collins 1973, Viparina & Just 1975, Úbeda et al 1999)

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