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.
Mabuya vitatta (Olivier) (Scincidae) and Agama stellio (L.) (Agamidae) were infected with Hemolivia mariae Smallridge et Paperna, 1997 by ingestion of tick viscera from Amblyomma limbatum Neumann, fed as nymphs on naturally infected Australian sleepy lizards, Tiliqua rugosa Gray. The unnatural infection apparently interfered with the developmental schedule of the parasites. Transmission electron microscopic images of merogonic stages were obtained, as well as images of early developing gametocytes. Tissue and intraerythrocytic meronts were bound by a hardened wall. Intraerythrocytic gametocytes were lodged in a parasitophorous vacuole, which was filled with granular material, and were bound by a two-membrane wall. Small and large osmiophilic bodies were located in a sub-pellicular position. With differentiation, the wall membranes tightened with the parasitophorous vacuole wall, and the osmiophilic bodies disappeared. The outer parasite membrane consolidated into a thick encasing with distinct sutures. Late infection in A. stellio comprised gametocytes only.