عنوان مقاله [English]
Sperm quality evalution is a valuable tool to study the reproduction potential of male animals and is important for breeding and preservation of medical species. In this study, 66 Zanjani male snakes were collected from two mountainous and cold habitats, Bostanabad in eastern Azarbaijan and Tarom of Zanjan Province of Iran, in year 2011 to 2012. Morphological characteristics of animals, including body weight, body length from snout to vent, specifications of vas deferen duct and sperm parameters including: concentration, motility, viability of sperm and also the presence and absence of ductal sperm were examined. Results show the morphology of vas deferens in Zanjani viper consists of three parts: proximal, median and distal. The longest values of vas deferen (right and left) lengths in Bostanabad viper was observed in the autumn and the shortest lengths in the spring, whereas these values for Tarom snakes were opposite. The highest mean percentage of sperm concentration in Bostanabad samples was observed in the spring and in Tarom samples was in the autumn. According to the results we can recommend concentration of mature sperms with suitable reproductive parameter are highest in the vas deferen in May, October and November and sperms with highest motility are present in the distal part of the duct in the spring and autumn, and it seems animal is ready for mating.