Full text
| |
| Author(s): |
Maristela Parra Miranda Vilela
Total Authors: 1
|
| Document type: | Doctoral Thesis |
| Press: | Piracicaba. , gráficos, ilustrações, tabelas. |
| Institution: | Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) |
| Defense date: | 2004-03-15 |
| Advisor: | Luciano Martins Verdade |
| Field of knowledge: | Agronomical Sciences - Animal Husbandry |
| Indexed in: | Banco de Dados Bibliográficos da USP-DEDALUS |
| Location: | Universidade de São Paulo. Biblioteca Central da Escola Superior de Agricultura Luiz de Queiroz; t639.394; M672i 83016 |
| Abstract | |
The goals of the present study were to asses the temperature sex determination partem for broad-snouted caiman (Caiman latirostris) and to evaluate the influence of both incubation and ambient temperature on the growth of hatchlings in captivity. Two experiments were carried out between December 2000 and October 2002. ln Experiment 1 eggs from the captive colony of ESALQ/USP were artificially incubated under different temperatures (28, 30, 32 and 34°C; precision: ± 0.5°C). Experiment 2 had two phases. On the first phase hatchlings produced at Experiment 1 were raised in environmental chambers with constant ambient temperature of 32°C(precision: ± 1°C). On the second phase hatchlings produced at the incubation temperature with highest eclosion rate (estimated based on the results of Experiment 1 as 31.8°C, precision ± 0.5°C) were raised in environmental chambers at different ambient temperatures (28, 30, 32 and 34°C; precision: ± 1°C). The results of Experiment 1 can be stated as follows: a) Only females were produced at 34°C; predominantly males were produced at 30°C, and males and females were produced between 30 and 32°C; b) Temperature-sex determination partem for the species in our conditions was Female-Male (FM) differing from the usual Female-Male-Female (FMF) pattern described for other crocodilians including the broad-snouted caiman in Argentina; c) Mortality of embryos was complete at 28°C; and, d) The temperature of incubation with maximum hatching success was estimated in 31.8°C with equal estimated proportions of males and females. The results of Experiment 2 can be stated as follows: a) Temperature of incubation did not influence growth rate and weight gain but affected cranial morphometrics on hatchlings; b) There was a significant clutch effect on the growth pattern of the hatchlings; e) Ambient temperature significantly affected growth rate and weight gain in hatchlings; and, d) Maximum growth rate and weight gain were obtained at 34°C. (AU) | |