Sarcocystis stenodactylicolubris n. sp., a new sarcosporidian coccidium with a snake-gecko heteroxenous life cycle

Oocysts/sporocysts of Sarcocystis sp. measuring 9.7 (9-10) x 7.6 (7-8) μm were found in the intestinal contents of the Dahl's whip snake Coluber najadum. Of wide spectrum of experimentally inoculated hosts, only species of the family Gekkonidae - Ptyodactylus guttatus and Stenodactylus grandiceps - were found to be susceptible intermediate hosts. Transparent, barely visible sarcocysts found in tail, limbs and tongue striated muscles of the geckoes were 175-200 μm x 35-50 μm in size at 78 DPI. Ultrastructurally, the primary cyst wall was characteristic by spine-like villar protrusions up to 800 nm long, 200-250 nm in diameter at their base, tapering to thinner apex. Protrusions appear typically lobular or irregular in the cross-sections. Back-transmission from P. guttatus to Coluber rogersi leaded to oocysts/sporocysts excretion since 38 days post infection. Based on sarcocyst morphology and experimental data, Sarcocystis stenodactylicolubris is apparently a new species. Based on obtained and already published results, Sarcosporidia parasitising colubrid snakes as definitive hosts are suggested to be family specific on the level of their intermediate host