Prehensile-Tailed Skink Subspecies Sexing
There are two currently recognized subspecies of the prehensile-tailed skink, the common or banded prehensile-tailed skink (Corucia zebrata zebrata) and the Bougainville prehensile-tailed skink (C. z. alfredschmidti).
The Bougainville skink has a green head with yellow throat, eyes with bright yellow irises, and bands on its body. It is further distinguished from the common skink by having seven instead of five parietal scales, and larger scales on its back and abdomen.
The common prehensile-tailed skink may be further differentiated by distribution; the islands of Guadalcanal, Isabel and Malaita each have distinct characteristics. Guadalcanal skinks are small and slender. They have yellow to red-brown heads that may be speckled with black, olive irises, and a green body with black spots and no obvious bands. Isabel skinks are very large and heavily built, with dull green heads and possibly dull yellow throats, dark brown irises, and sharply edged bands on the bodies. Malaita skinks are built like Isabel skinks but somewhat smaller. They have heads that are a dull olive green with possibly dull yellow throats, yellow to olive irises, and high-contrast bands on their bodies. Allegedly, the Bougainville, Isabel and Guadalcanal skinks are more tractable than the feisty Malaita. It is likely that this scheme has overlooked distinct genetic populations; I am unaware if any genetic work has been completed to sort out what is going on with the prehensile-tailed skinks. I have noticed some skinks have a large, bright-white or yellow rostral scale and different eye colors than those reported. The Schmidt descriptions are often unhelpful in sorting out a mixed group of skinks as there are no truly objective descriptions published; furthermore, hybridization has likely mixed the characteristics quite a bit in captive skinks.
Accurately Sexing Skinks
Your skinks must be correctly sexed in order to have a successful breeding program. I have seen several same-sex pairs sold as male-female pairs. Female-female pairs may even lay infertile slugs in the cage, mimicking a male-female pair that isn’t compatible. Enough female skinks have the broad head and prominent jowls of male skinks and enough male skinks look like female skinks to make it worthwhile to have a veterinarian properly sex your skinks.
Sexing is a simple process. The skink is anesthetized with a rapid-acting inhaled anesthetic, such as Sevoflurane, and the genitals are everted (popped). This cannot be done consistently on a conscious male skink without the risk of damaging the hemipenes. Sexed pairs or trios of one male and two females work well together.
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