CICYTTP   12500
CENTRO DE INVESTIGACION CIENTIFICA Y DE TRANSFERENCIA TECNOLOGICA A LA PRODUCCION
Unidad Ejecutora - UE
artículos
Título:
Corticosterone plasma levels of embryos and hatchlings broad-snouted caiman (Caiman latirostris) incubated at different temperatures.
Autor/es:
MARÍA V. PARACHÚ MARCÓ; CARLOS I. PIÑA; GUSTAVO M. SOMOZA; GRACIELA JAHN; ELISA O. PIETROBON; JOSEFINA L. IUNGMAN
Revista:
The South American Journal of Herpetology
Editorial:
Brazilian Society of Herpetology
Referencias:
Lugar: Washington, DC; Año: 2015 vol. 10 p. 50 - 57
ISSN:
1808-9798
Resumen:
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 that stress hormones (corticosterone) can influence sex ratios in some reptiles. To explore this, we measured the levels of corticosterone in Caiman latirostris, to determine if the incubation temperature affects plasma corticosterone levels. Caiman eggs, taken from wild nests just after laying, were incubated at different temperatures (31, 33 and 34°C) until hatching. Plasmatic corticosterone was determined by radioimmunoassay in embryos, after the temperature-sensitive period and in hatchlings. We obtained 100% of females at 31°C and 100% of males at 33 and 34°C incubation temperatures. Differences among nests were observed in plasma corticosterone. However, hormone levels showed no differences between sexes or incubation temperatures in Caiman latirostris embryos or hatchlings. Corticosterone levels in embryos incubated at 31°C ranged from 0.01 to 2.2 ng/ml, in those incubated at 33°C the levels ranged from 0.01 to 4.65 ng/ml and, finally embryos incubated at the highest temperature 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.