Effect of egg rotation on embryo survival

PABLO A. SIROSKI; ALEJANDRO LARRIERA; GISELA L. POLETTA

Lake Charles, Louisiana.

Congreso; 23rd Working Meeting of the Crocodile Specialist Group; 2014

In crocodilians ranching programs, eggs harvest is one of the most critical steps to ensure maximum survival of embryos. It is broadly known that one extremely important factor to be taken into account in eggs collection is the maintenance of the same position in which they are found in the nest during all the incubation, and avoiding denting of the eggshell to ensure the maximum chance of hatching success. In general, eggs collection involves different steps that include handling by local people who identifies the nests, an eventual intermediary stage into carry containers, and the final transfer to the incubation container. Besides, most of the time, nesting habitat are far from program facilities, implying long ways transportation of the eggs on foot or by horse, and then driving through unpaved roads, etc. All these are potential causes of embryo mortality. If we considering that the eggs sometimes arrive to the program facilities in a wrong or altered the upright position, and the decision to rotate them to the right position must be taken at the moment. The aim of this study was to evaluate the effect of rotation at different periods of the incubation in the survival and size of embryos in order to define the maximum moment or tolerance up to which is possible to modify egg position.