Corticosterone Plasma Levels of Embryos and Newly Hatched Broad-snouted Caiman (Caiman latirostris) Incubated at Different Temperatures

PARACHU MARCO MV; PIÑA CI; SOMOZA GM; JAHN GA; PIETROBON EO; IUNGMAN JI

South American Journal of Herpetology

BioOne

Lugar: Washington; Año: 2015 vol. 10 p. 50 - 57

1808-9798

The temperature-sensitive period is the time during development at which sex determination occurs in temperature-dependent sex determination vertebrates, such as in caimans. The interplay among temperature and steroid hormones is also known, and has been suggested that stress hormones (corticosterone) may influence sex ratios in some reptiles. To explore this, we measured the levels of corticosterone in Caiman latirostris, to determine if the incubation temperature (31, 33 and 34°C) affects plasma corticosterone levels. Differences among nests were observed in plasma corticosterone. However, hormone levels showed no significant differences between sexes or incubation temperatures in Caiman latirostris embryos or hatchlings. Corticosterone levels in embryos incubated at 31°C (100% of females) ranged from 0.01 to 2.2 ng/ml, in those incubated at 33°C (100% of males) the levels ranged from 0.01 to 4.65 ng/ml and, finally embryos incubated at the highest temperature (100% ofmales) ranged from 0.01 to 6.31 ng/ml. Hatchlings presented higher levels of corticosterone: those produced at 31°C ranged from 1.11 to 39.18, at 33°C from 2.85 to 22.36 and 34°C 2.72 to 39.05 ng/ml.