Ultrastructural study of Sarcocystis muriviperae development in the intestine of its snake hosts.

The ultrastructure of the endogenous stages--merozoites, microgamonts, macrogamonts and oocysts, of Sarcocystis muriviperae from the snakes Vipera palaestinae and Coluber jugularis is described. Snakes were infected via white mice fed on sporocysts obtained from naturally infected snakes of the same species. Snakes examined 4 days post-infection contained only young and premature gamonts. Infection in snakes sacrificed on day 7 post-infection consisted predominantly of mature microgamonts and macrogamonts; snakes examined on day 10 post-infection revealed only oocysts. The fine structure of the endogenous stages from the two snakes, including size and contents of the wall-forming bodies, was identical, confirming their suggested conspecificity. Observed endogenous stages also conformed in their major details with the same developmental stages of other Sarcocystis species studied from other snakes and mammalian definitive hosts and from in vitro culture. However, they differed from the latter in size and contents of the wall-forming bodies. The observed fertilization process was reminiscent of that described earlier in S. bovicanis.