| Artificial incubation of 558 eggs from 70 clutches of Trachemys dorbignyi (Duméril & Bibron, 1835) were performed at São Paulo Zoo during 1992 and 1993. Hatching occurred when eggs were incubated between 25 and 31.5oC. Incubation time varied from 54 (at 31.5oC) to 120 days (at 25oC), similarly to Trachemys scripla sspp. Hatchling used the caruncle to made small incisions in the egg shell, latter enlarged by movements of the head and forefeet. Hatching usually lasted from one to two days. Newborn's carapace and plastron showed their natural form few hours after the emergence from the egg shell. During the third or fourth week, caruncle usually disappeared, and yolk sac was completely absorbed. Average (x±sd) measures of newborn were 3.55±0.18cm of... |
