Meeting Abstract

4.3  Wednesday, Jan. 4  How froglets pay the price: carry-over effects on morphology and performance in response to pond drying CHARBONNIER, J.F*; VONESH, J.R; Virginia Commonwealth University, Richmond; Virginia Commonwealth University, Richmond charbonnierj@vcu.edu

Animals with complex life cycles cope with environmental uncertainty by altering life history switchpoints through developmental plasticity. This plasticity may impact morphology, locomotor performance, and survival in later life stages. Hydroperiod is an important factor which may alter life history switchpoints in aquatic organisms. Many amphibians can plastically respond to changes in hydroperiod, but few studies have examined the post-metamorphic costs of this plasticity. To investigate the potential carry-over effects of plasticity to reduced hydroperiod, we studied the Tungara frog, Physalaemus pustulosus a tropical anuran which breeds in highly ephemeral habitats. We conducted a field study with three different water level treatments (Constant high volume, constant low volume, and decreasing water volume) in 60 L mesocosms and measured time and size to metamorphosis, tibiofibula length and jumping performance. We also conducted a complimentary laboratory study which similarly manipulated water levels, and also manipulated resource levels. In our field experiment, frogs from decreasing water volumes emerged earliest and had smaller body size. In our laboratory study, frogs from the low volume treatment emerged earliest and had smaller body size. In both studies, froglets from decreasing water treatments had shorter tibiofibulas relative to their size and reduced jumping performance. Our results demonstrate that animals which display plasticity in the timing of ontogenetic shifts may experience costs on their morphology and performance later in life. We interpret these results within the context of past studies which manipulate how hydroperiod may impact amphibian development.