Anotace:
This study illustrates the main morphological structures of the cloaca of six adult horned vipers Vipera ammodytes (3.3). The coprodeum is characterized by smooth and thin mucosa, with moderate vasculature. In the centre of the coprodeum the anal sphincter is located, which separates the coprodeum from the colon. Structures of the urodeum are divided by two highly developed septa in female vipers. The urodeum in female vipers is characterized by distinct chambers, which become visible immediately behind the exit of the sphincter of the coprodeum. Vaginal pouches leading to the entrance of the oviduct are visible. The male urodeum is characterized by two distinct structures. In the upper part of the urodeum, the coprodeum sphincter surrounded by a gently folded mucosa, and the urethral papillae surface on a large mucosal protrusion emerging from the dorsal urodeum are visible in male horned vipers. The mucosal protrusion that hosts the urethral papillae can be found in two different appearances, closed or open. The proctodeum is a tubular and muscular structure that leads to the vent. Cloacoscopy is as a safe and effective method for cloaca exploration in both sexes of the horned viper. This technique may be used to assist artificial insemination in the horned viper in the future.