Abstract
A new species of
Isospora
Schneider, 1881 was discovered in the Mediterranean house gecko,
Hemidactylus turcicus
(Linnaeus) in Saudi Arabia. Both exogenous (sporulated oöcysts) and endogenous developmental stages (meronts, gamonts) were studied and measured. Sporulated oöcysts are spheroidal to slightly subspheroidal, 17–22 (18) µm wide, with a smooth, bi-layered oöcyst wall; micropyle, polar granule and oöcyst residuum are all absent. Sporocysts are ovoidal, 9–11 × 6–8 (10 × 7) µm, with both Stieda and sub-Stieda bodies, a dispersed granular sporocyst residuum, and four sporozoites. Endogenous stages develop extranuclearly in the cytoplasm of epithelial cells of the small intestine. Early uninucleate meronts are spheroidal,
c.
3–5 (4) µm wide. Multinucleated meronts are subspheroidal, 11–15 × 9–12 (13 × 10) µm, but mature meront and merozoites were not seen. Mature microgamonts, with up to 60 microgametes, are spheroidal, 11–15 (13) µm; macrogamonts are subspheroidal, with a prominent central nucleus, and measured 11–14 × 7–10 (12 × 8) µm.