Ultrasound sex determination in snakes: correlation between hemipenes or hemiclitorids and body morphological parameters

In practice, snakes’ sex is mostly determined us- ing invasive techniques such as probing, popping or endoscopy. Ultrasonography has been used as a high sensitivity and non invasive technique in snake’s sex determination since 2009, but few studies are still available and none of them ever considered the dimensions of copulatory organs or tried to correlate them to the morphometric parameters of snakes. From August to October 2016, fifty snakes of the Pythonidae, Boidae and Colubridae families un- derwent the ultrasonographic examination of hemipenes and hemiclitoris in order to confirm their sex. Hemipenes and hemiclitoris (right and left) length, height and width were ultrasono- graphically measured in longitudinal and trans- verse scans of the cloacal region. At the same time, the body length, the tail length, the head length and width and the diameter of the cloacal segment of each snake was measured and recorded on a worksheet. The procedures never required anesthesia or sedation of the snakes, which were only manually restrained. We confirm that ultrasonography is a sensitive, safe and harmless technique for snakes’ sex de- termination. In addition, we found statistically significant correlations between hemipenes and morphometric parameters, but no correlation was found involving the hemiclitoris.