Follicular Growth Evaluation, Oviposition and Egg Hatching in the Ball Python (Python regius)

Reproductive performance and follicular dynamics in captive female ball pythons (Python regius) were investigated to evaluate reproductive efficiency, assess the usefulness of ultrasonography, and examine the relationship between follicular size and ovulation timing. Reproductive parameters included follicular development, ovulation rate, ovulation-to-oviposition interval, egg quality, and hatching success. Monthly ultrasonographic examinations were performed from March to August using a 7.5 MHz linear probe, and the findings were compared with manual palpation. Overall, 58.3% of females ovulated and laid eggs. Ovulation occurred mainly between April and August, whereas egg laying took place from June to November. The median clutch size was six eggs, and incubation lasted approximately 58 days. Ultrasonography effectively monitored follicular development, showing progressive changes in echogenicity and significant increases in follicular diameter throughout the breeding season. A strong negative correlation was found between follicular size and days to ovulation (r = −0.88; p < 0.001). Follicles measuring ≥20 mm showed a median growth rate of 0.38 mm/day. Manual palpation showed lower diagnostic accuracy, with a 25% false-negative rate. This study provides baseline reproductive data that may improve captive breeding management, animal welfare, and future reproductive research, including the development of reproductive biotechnologies in this species.