Sex determination has a fundamental role in a captive breeding context, both for commercial reasons and in relation to animal welfare itself.However, this can be particularly difficult, especially in reptiles with little or no sexual dimorphism.Twenty-three clinically healthy young Sierra Nevada lizards (Timon nevadensis) were included in this study for sex determination.The first attempt at sexing was carried out by cloacal probing.
A small, buttoned probe was inserted very gently into the hemipenal Accessories pouches, and the length of the inserted part was evaluated and measured.Subsequently, for each animal, a contrast medium was administered into the cloaca, and radiography was performed within 5 min.Through probing, 11 males and 8 females were recognized.The test was, however, equivocal in four subjects.
In contrast radiography, 14 males and 9 females were identified.All the animals were rechecked after 8 months through an ultrasound examination, confirming 15 of the 14 previously male sexed animals based on contrast radiography.All the animals identified as female (n = 9) by contrast Sports Bra radiography were confirmed.From these results, it seems that contrast radiography may have major sensitivity in sex determination compared to probing.
This technique could represent a valid and less invasive aid for sexing young lizards.