Stress hormones mediate predator-induced phenotypic plasticity in amphibian tadpoles
Open Access
- 7 May 2013
- journal article
- Published by The Royal Society in Proceedings Of The Royal Society B-Biological Sciences
- Vol. 280 (1758), 20123075
- https://doi.org/10.1098/rspb.2012.3075
Abstract
Amphibian tadpoles display extensive anti-predator phenotypic plasticity, reducing locomotory activity and, with chronic predator exposure, developing relatively smaller trunks and larger tails. In many vertebrates, predator exposure alters activity of the neuroendocrine stress axis. We investigated predator-induced effects on stress hormone production and the mechanistic link to anti-predator defences in Rana sylvatica tadpoles. Whole-body corticosterone (CORT) content was positively correlated with predator biomass in natural ponds. Exposure to caged predators in mesocosms caused a reduction in CORT by 4 hours, but increased CORT after 4 days. Tadpoles chronically exposed to exogenous CORT developed larger tails relative to their trunks, matching morphological changes induced by predator chemical cue; this predator effect was blocked by the corticosteroid biosynthesis inhibitor metyrapone. Tadpole tail explants treated in vitro with CORT increased tissue weight, suggesting that CORT acts directly on the tail. Short-term treatment of tadpoles with CORT increased predation mortality, likely due to increased locomotory activity. However, long-term CORT treatment enhanced survivorship, likely due to induced morphology. Our findings support the hypothesis that tadpole physiological and behavioural/morphological responses to predation are causally interrelated. Tadpoles initially suppress CORT and behaviour to avoid capture, but increase CORT with longer exposure, inducing adaptive phenotypic changes.Keywords
This publication has 54 references indexed in Scilit:
- Molecular mechanisms of corticosteroid synergy with thyroid hormone during tadpole metamorphosisGeneral and Comparative Endocrinology, 2010
- Re-evaluating the costs and limits of adaptive phenotypic plasticityProceedings Of The Royal Society B-Biological Sciences, 2009
- FORM, FUNCTION, AND FITNESS: PATHWAYS TO SURVIVALEvolution, 2008
- Predator threat induces behavioral inhibition, pituitary-adrenal activation and changes in amygdala CRF-binding protein gene expressionPsychoneuroendocrinology, 2007
- Ecological consequences of phenotypic plasticityTrends in Ecology & Evolution, 2005
- Evolution of phenotypic plasticity: where are we going now?Trends in Ecology & Evolution, 2005
- ARE INDUCED DEFENSES COSTLY? CONSEQUENCES OF PREDATOR-INDUCED DEFENSES IN WESTERN TOADS, BUFO BOREASEcology, 2003
- Predators as stressors? Physiological and reproductive consequences of predation risk in tropical stonechats (Saxicola torquata axillaris)Proceedings Of The Royal Society B-Biological Sciences, 2001
- How Do Glucocorticoids Influence Stress Responses? Integrating Permissive, Suppressive, Stimulatory, and Preparative ActionsEndocrine Reviews, 2000
- Seasonal and stress related changes in plasma gonadotropins, sex steroids, and corticosterone in the bullfrog, Rana catesbeianaGeneral and Comparative Endocrinology, 1983