A comparative analysis of female genitalia of seven Old World snakes using a recently proposed technique

Abstract

The diversity of genitalia has long intrigued evolutionary and functional morphology scientists, with a primary focus on male copulatory organs. Despite extensive studies on snake genitalia, particularly hemipenes, female copulatory organs remain understudied. This research aims to fill this gap by using a recently introduced methodology for preparation with a few adjustments, and by describing female snake genitalia for seven previously undescribed species. The methodology is based on employing a two-component condensation silicone into snakes’ genitalia to create internal models for intersexual comparative morphology. We conducted a comprehensive examination of seven Old World snake species - Boidae: Eryx jaculus, Colubridae: Dolichophis caspius, Zamenis longissimus, Elaphe quatuorlineata, Coronella austriaca, and Viperidae: Vipera ammodytes, and V. berus. Our results reveal conspicuous variations in female genitalia morphology, speculating that there is also a significant variation in copulation adjustment between the different types of species’ genitalia.