Absence of daily cycles in plasma sex steroids in male and female tuatara (Sphenodon punctatus), and the effects of acute capture stress on females.

@article{Cree1990AbsenceOD,
  title={Absence of daily cycles in plasma sex steroids in male and female tuatara (Sphenodon punctatus), and the effects of acute capture stress on females.},
  author={Alison Cree and Louis J. Guillette and John F. Cockrem and Mark Ashley Brown and Geoffrey Keith Chambers},
  journal={General and comparative endocrinology},
  year={1990},
  volume={79 1},
  pages={103-13}
}
The possible existence of daily cycles in plasma concentrations of sex steroids was examined in wild male and female tuatara (Sphenodon punctatus). Samples were collected from freshly captured animals at dusk, middle of the night, dawn, and middle of the day in January (summer) and July (winter). Males showed daily cycles in mean body temperature (Tb) in both seasons but no daily cycle in mean plasma testosterone concentration in either season. Vitellogenic female tuatara in January and females… CONTINUE READING