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.
Parasitological examination of faeces of 26 snakes kept in Bio-Ken Snake Farm, Watamu, Kenya revealed new species of Eimeria Schneider, 1875 in Telescopus semiannulatus Smith, 1849. Oocysts of Eimeria arabukosokokensis sp. n. are cylindrical 26.8 (25-29) × 15.1 (14-16) µm with smooth, bilayered oocyst wall and a single polar granule. The broadly ellipsoidal sporocysts average 9.3 (8.5-10) × 7.1 (6.5-7.5) µm and possess single-layered wall composed of two plates joined by longitudinal suture. Caryospora cf. regentensis Daszak et Ball, 2001 is reported from Dendroaspis angusticeps (Smith, 1849) and two additional forms of Caryospora Léger, 1904 are reported and morphologically characterised from a single specimen of Psammophis orientalis Broadley, 1977. Systematic status of Caryospora spp. in sub-Saharan Psammophis Boie, 1827 is discusses and all species reported by various authors to date are suggested to be treated as species inquirendae until more detailed data on these parasites and their hosts are available.
Oocysts/sporocysts of Sarcocystis sp. were found in the intestinal contents of the smooth snake, Coronella austriaca I .aurenti. Common voles Microtus arvalis (Pallas), bank voles Clethrionomys glareolus (Schreber), green lizards Lacerta viridis (Laurcnti), and common wall lizards Podarcis muralis (Laurenti) were experimentally inoculated as potential intermediate hosts. Only common wall lizards were found to be susceptible intermediate hosts. Transparent, macroscopically hardly visible sarcocysts found in tail striated muscles of lizards were 480 (390-640) x 210 (190-230) pm in size 72 days post-infection. Using the light microscopy, the sarcocyst wall was about 1 pm thick with an apparent layer of villi approx. 2 pm thick. Ullraslruclurally, the primary cyst wall was characterised by spine-like villar protrusions up to 2.5 pm in length and 0.5 pm in diameter. Based on sarcocyst morphology and experimental data, the discovered Sarcocystis species is suggested to be conspccific with Sarcocystis lacertae Babudieri, 1932. A redescription of Sarcocystis lacertae is presented in this study.
Caryospora duszynskii Upton, Current et Barnard, 1984 was successfully transmitted to snakes of the genus Elaphe by feeding them previously infected mice. Fifty thousand oocysts were orally administered to two mouse strains, BALB/c and Crl:CD-1(ICR)BR, which were subsequently fed to captive-born coccidia-free Elaphe guttata (L.) in two respective independent experiments. Both E. guttata expelled C. duszynskii oocysts in their faeces, beginning on day 18 and 26 post infection (p.i.) and shed oocysts continuously through the end of the experiment, day 230 and 135 p.i., respectively. There were no parasitic stages or lesions in mice, as revealed by histological examination. Experiments proved that rodents serve as paratenic hosts for C. duszynskii. In summary we discuss the life-cycle strategies of Caryospora spp. in reptiles and present three general modes of their development.