کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2799833 | 1568877 | 2016 | 5 صفحه PDF | دانلود رایگان |
• Tadpole whole body CORT is elevated at 1–20 min post-exposure to predator cues.
• Tadpole CORT response to predator cues parallels acute responses to stressors.
• Older, predator-naïve tadpoles show a diminished acute response to predator cues.
• Older, predator-conditioned tadpoles show no acute response to predator cues.
Anuran larvae exhibit behavioral and morphological plasticity in response to perceived predation risk, although response type and magnitude varies through ontogeny. Increased baseline corticosterone is related to morphological response to predation risk, whereas the mechanism behind behavioral plasticity remains enigmatic. Since tadpoles alter behavioral responses to risk immediately upon exposure to predator cues, we characterized changes in whole body corticosterone at an acute (<1 h post-exposure) timescale. Tadpoles (Lithobates sylvaticus) at Gosner stage (GS) 25 (free-swimming, feeding larvae) increased corticosterone levels to a peak at 10–20 min post-exposure to predator cues, paralleling the acute stress response observed among other taxa. Tadpoles reared for 3 weeks (mean GS29) with predation risk (caged, fed Aeshnid dragonfly nymph) had lower corticosterone levels at 10–20 min post-exposure to dragonfly cues than predator-naïve controls, suggesting habituation, although the magnitude of increase was markedly diminished when compared to younger tadpoles (GS25). These experiments represent the first assessment of tadpole hormonal responses to predation risk at the acute timescale. Further research is required to establish causality between hormonal responses and behavioral changes, and to examine how and why responsiveness changes over ontogeny and with chronic exposure to risk.
Journal: General and Comparative Endocrinology - Volume 229, 1 April 2016, Pages 62–66