Meeting Abstract

90.2  Friday, Jan. 7  The long-term developmental and physiological effects of larval environmental stressors are condition-dependent in wood frogs WARNE, R.W.*; CRESPI, E.J.; Vassar College Biology; Vassar College Biology rw.warne@gmail.com

Exposure to stressors during early development can impact physiological function, behavior, and fitness in adult life stages in vertebrates. However, the specific mechanisms that link these early experiences to adult phenotypes are poorly understood. Here we explored how reduced resource availability and pond drying affect growth, development, and neuroendocrine stress axis function in larval and adult wood frogs. We reared replicate populations in mesocosms of both high and low food. At Gosner stage 38 tadpoles were transferred to tubs with high or low water until metamorphosis. Juvenile frogs were housed for 10 weeks when baseline and stress-induced plasma corticosterone was assayed. Although animals subjected to low food metamorphosed at the same time as the high-food animals they did so at half the body weight. Pond drying caused further weight reduction and elevated corticosterone levels, but did not accelerate development time. The long-term effects of these larval stressors on adult frogs were only apparent when combined. Frogs that experienced low food and low water had faster size-specific growth rates, and at 10 weeks of age exhibited elevated baseline corticosterone concentrations. Frogs that developed under cumulative stressors also showed a blunted stress response to a handling test, suggesting that glucocorticoid and CRF receptor expression may be down regulated. These results suggest that environmental stressors during early development can program neuroendocrine stress axis function in adult frogs, but such long-term effects depend on a tadpole’s nutritional condition at the time of stress exposure. These findings provide insight into how intrinsic and extrinsic factors during larval stages influence adult physiology and fitness.