evaluation of reproductive parameters of vas deferens sperms in caucasian snake (gloydius halys caucasicus)

reproductive parameters evaluation is considered as helpful tool for gene bank formation in ecological and economically important animals species. gloydius halys caucasicus is venomous, viviparous pit viper of northwest of iran. in this research, the spermatic reproductive parameters of this taxon were studied. twenty six male snakes were collected from takht-e-soleiman region between september and october, 2010. findings revealed that male snakes with body length of 45.07 ± 2.83 cm and body weight of 51.50 ± 10.42 g, and right and left gonads volume of 0.12 ± 0.03 ml and 0.06 ± 0.01 ml are mature ones and sperms concentration in first, middle and final regions of vas deferens duct were, 22.30 ± 19.34 ×106 ml-1, 30.34 ± 11.55 ×106 ml-1, and 37.65 ± 16.46×106 ml-1, respectively. the sperms motility at three regions of duct were 60.53%, 62.07%, and 60.00% and percentage of immotile sperms in these regions were 39.46%, 37.92%, and 39.84%, respectively. percentage of morphologically normal sperms was 69.23 ± 10.57% and abnormal sperms was 30.76 ± 10.57%; including 12.69 ± 5.25% spiral tailed, 7.33 ± 4.37% coiled tailed and 4.16 ± 2.51% folded tailed sperms. percentage of live sperms in the first, middle and final regions of duct were 55.76 ± 10.77%, 58.84 ± 12.77%, and 57.69 ± 9.91%, respectively and percentage of dead sperm in these regions were 44.23 ± 10.77%, 41.15 ± 12.77%, and 42.30 ± 9.91%, respectively. results suggested, mature sperms with acceptable reproductive quality could be collected from gloydius halys caucasicus snake of iran between september and october.