MCCOY, Krista A*; AMICK, Alison M; University of Florida; University of Florida: Metamorphosis and reproductive growth and development
Plasticity in size at and time to metamorphosis in amphibians is well documented. For example, tadpoles developing in temporary ponds will quickly metamorphose in response to decreasing water levels resulting in small size at metamorphosis. Thus, strong tradeoffs exist between development and growth when environmental conditions are poor. Amphibians that metamorphose at larger sizes survive better and reproduce at younger ages than animals that metamorphose at smaller sizes. One possible reason for this relationship is that small metamorphs may not be in adequate condition to reproduce in their first year. We hypothesize that individuals in less hospitable environments may also allocate more energy to development of structures necessary for metamorphosis than toward growth or development of gonads (because they are not immediately required). Few, if any, studies have explicitly tested whether the growth or developmental rates of amphibian gonads can vary, or whether reproductive structures exhibit tradeoffs in growth and development similar to those commonly found in the soma during metamorphosis. We test the hypotheses that 1) animals fed a restricted diet would have less developed or smaller gonads at metamorphosis than those fed large quantities (exhibit plasticity), and 2) in food restricted environments tradeoffs exist where gonad development is maximized while gonad growth is sacrificed. These types of tradeoffs could occur when reproductive organs exhibit plasticity in their growth and development. The ability to differentially allocate energy between somatic and reproductive growth and development could be an important mechanism used to maximize the development of structures required for metamorphosis (i.e. limbs, or carnivore gut) when environmental conditions are unfavorable. Furthermore, tradeoffs within the gonad during development could influence fecundity and life time fitness.