Assessment of Reptilian early egg viability and prediction of hatch dates development
Assessment of Reptilian early egg viability and prediction of hatch dates development from ZSL - London Zoo
A better way of assessing development in reptilian eggs
Most reptile eggs are incubated artificially in captive breeding conditions.
Early detection of viable eggs means that infertile or non-developing eggs can be rapidly excluded from the incubation unit as these are potential sources of infection. Traditionally, candling has been used to detect embryonic development but one disadvantage is that embryonic death is not immediately obvious and, in certain species, candling is only useful quite late in development or may be of limited use in thick-shelled species.
The use of a portable digital egg monitor, developed for bird eggs, was used to investigate the viability of Testudines, Sauria and Serpentes eggs. The Buddy® monitor uses a single or triple LED light source emitting infra-red light and a light sensor which detects the variation in intensity of absorbed versus reflected infra-red light caused by arterial pulsatile vasculature within the developing fertile egg membranes.
The technique has proven to be a more reliable method than candling in establishing viability in all species monitored and predictable trends in heart rates prior to hatching certain species has been established. These results have significant management implications for the conservation breeding of reptile species. By rapidly assessing egg viability non-viable eggs can be removed from incubators early on in the incubation period, reducing the risk of contamination to fertile eggs.
In addition, certain eggs, most notably Komodo dragon (Varanus komodoensis) eggs, have not shown viability by traditional candling methods.
Dragon eggs may have been discarded in the past. The Buddy® monitor has proven effective at detecting such eggs.
Developed by: ZSL - London Zoo