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Dynamic endocrine responses to stress: evidence for energetic constraints and status dependence in breeding male green turtles

Version 2 2024-06-06, 11:12
Version 1 2017-05-03, 13:43
journal contribution
posted on 2024-06-06, 11:12 authored by TS Jessop, R Knapp, JM Whittier, CJ Limpus
During reproduction, male vertebrates may exhibit a continuum of interactions between sex and adrenal steroids during stressful events, the outcome of which may be important in either reducing or promoting male reproductive success. We studied adult male green turtles (Chelonia mydas) to examine if they altered plasma corticosterone (CORT) and androgen levels in response to a standardized capture/restraint stressor as potential mechanisms to maintain reproductive activity during stressful events. At the population level, we found that migrant breeding males had a significantly smaller CORT response to the capture/restraint stressor compared to nonbreeding males and that this decreased response coincided with the generally poorer body condition of migrant breeders. In contrast, plasma androgen levels decreased significantly in response to the capture/restraint stressor in migrant breeding males, but not in nonbreeding and pre-migrant breeding males. For individual migrant breeding males, the magnitude of their CORT and androgen responses to the capture/restraint stressor was highly correlated with their body condition and body length, respectively. Our results demonstrate that male green turtles exhibit complex interactions in their endocrine responses to a capture/restraint stressor and that variation in these interactions is associated with differences in males' reproductive, energetic, and physical state. We hypothesize that interplay between physical status and plasma hormone responses to stressors could have important consequences for male green turtle reproduction.

History

Journal

General and comparative endocrinology

Volume

126

Article number

1

Pagination

59-67

Location

Amsterdam, The Netherlands

ISSN

0016-6480

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2002, Elsevier Science

Issue

1

Publisher

Elsevier