title: Reproduction in shark-attacked sea turtles is supported by stress-reduction mechanisms.
abstract: Vertebrates exhibit varied behavioural and physiological tactics to promote reproductive success. We examined mechanisms that could enable female loggerhead turtles to undertake nesting activities and maintain seasonal reproduction despite recent shark injuries of varying severity. We proposed that endocrinal mechanisms that regulate both a turtle's stress response and reproductive ability are modified to promote successful and continued reproduction. Irrespective of the degree of injury, females did not exhibit increased levels of the stress hormone corticosterone, nor decreased levels of the reproductive steroid testosterone; hormone responses consistent with stress. When exposed to a capture stressor, females with shark injury did not exhibit any greater corticosterone response than controls. In addition, breeding females showed a reduced corticosterone stress response compared to non-breeding females. Reduced endocrinal responses following shark injury, and during breeding in general may, in part, enable females to maintain behavioural and physiological commitment to reproduction.
authors.affiliation: Center for Reproduction of Endangered Species, Zoological Society of San Diego, San Diego, CA 92112, USA. tjessop@sandiegozoo.org
authors.forename: Tim
authors.initials: T
authors.lastname: Jessop
authors.forename: Joanna
authors.initials: J
authors.lastname: Sumner
authors.forename: Val
authors.initials: V
authors.lastname: Lance
authors.forename: Col
authors.initials: C
authors.lastname: Limpus
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D003345:Corticosterone / Q000097:blood; D005260:Female; D009425:Nesting Behavior / Q000502:physiology*; D010140:Pacific Ocean; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000502:physiology*; D012098:Reproduction / Q000502:physiology*; D013312:Stress, Physiological / Q000503:physiopathology*; D013739:Testosterone / Q000097:blood; D014426:Turtles / Q000293:injuries* / Q000502:physiology*
chemical_list: D013739:Testosterone; D003345:Corticosterone