A new coccidian parasite of the genus Caryospora Léger is described from the colubrid snake Boiga dendrophila Boie, 1827 imported from Kalimantan. Oocysts of Caryospora kalimaniunensis sp. n. are spherical, 18.7 (17.0-20.0) pm in diameter, with a bilayered slightly pitted and brownish oocyst wall. A micropyle and oocyst residuum are absent. One globular polar granule is present in 45% of sporulated oocysts. Sporocysts are ovoidal to ellipsoidal, 14.5 (13.0-15.5) x 10.5 (10.0-11.0) pm, with prominent Stieda and substieda bodies. Sporocyst residuum is present as small granules scattered among sporozoites. Sporozoites are elongate, lying lengthwise and parallel within the sporocyst and completely filling the sporocyst. Each sporo-zoite contains a spherical anterior and posterior refractile bodies.
Parasitological examination of two ornate Nile monitors Varanus ornatus (Daudin, 1803) imported from Benin revealed the presence of a new species of Caryospora. Oocysts of Caryospora varaniornati sp. n. are spherical to slightly subspherical, 12.0 (11-12.5) × 11.5 (11-12) µm, without a micropyle and oocyst residuum, and occasionally possessing one small polar granule. Sporocysts are broadly ellipsoidal, 8.8 (8.5-9.5) × 6.7 (6.5-7) µm; a lentil-like Stieda body is present, ca. 0.5 × 1 µm; substieda body not visible. Experimental infection of a closely related host, Varanus niloticus (L.), did not lead to the oocyst excretion despite the fact that one of the experimentally inoculated monitors was immunosuppressed by dexamethasone. Histological examination did not reveal stages of coccidian development. Therefore, it is possible that C. varaniornati is strictly host specific.
Seven of 12 lacertid lizards Acanthodactylus boskianus (Daiidin, 1802), passed oocysts of an Isospora species. Comparison with other species of the genus Isospora Schneider, 1881 indicated that found coccidium represented a new species, for which the name /. abdallahi is proposed. Sporulated oocysts of /. abdallahi are spherical or subspherical, 25.8 (24.5-29.0) x 23.9 (23.0-25.5) pm, shape index (length/width) being 1.07 (1.00-1.16), with a smooth, bilayered oocyst wall that is slightly yellowish, about 2 pm thick. Micropyle, oocyst residuum and polar granule are absent. Sporocysts are ovoidal, 15.4 (14.0-16.0 x 9.4 (9.0-10.0) pm, with smooth and colorless sporocyst wall, shape index 1.6 (1.5-1.8). Stieda body is dome-like, substieda body spherical to subspherical. Sporocyst residuum is composed of numerous granules of different size, scattered among sporozoites. Most oocysts are passed unsporulated; sporulation was completed within 12 h at 25'C. Endogenous development occurs inside nuclei of enterocytes in the small intestine.
During a survey of the coccidian parasites of reptiles, caryosporan oocysts were found in the faeces of wild and captive European viperid snakes Vipera berus (L.) and V. ammodytes (L.). Thirty two of 37 examined V. herus (86%) and 9 of 17 examined V. ammodytes (53%) specimens were found to be passing caryosporan oocysts. Morphological characters of all caryosporan isolates were identical and fitted well with the description of Caryospora simplex Léger, 1904. Experimental inoculation of severe combined immunodeficient (SC1D) mice with seven isolates of C. simplex from V. berus or V. ammodytes confirmed the heteroxenous life cycle pattern, for the first time for isolates of evidently European origin. Caryosporan developmental stages were observed in the connective tissues of the nose, cheeks, ear and scrotum in all inoculated SCID mice. V. berus and V. ammodytes represent new hosts for C. simplex. The present paper represents the first widely based report on coccidian parasites of the genus Caryospora Léger in European viperids. Our findings indicate a wide distribution of C. simplex throughout the range of distribution of snakes of the genus Vipera.