[The life-history of Sarcocystis singaporensis Zaman and Colley, 1976 in the definitive and intermediate host (author's transl)].

Sporulated oocysts and sporocysts (9.3 x 7.3 micrometer) of Sarcocystis singaporensis - isolated from freshly imported snakes (Python reticulatus) - were fed to various animals to test their function as suitable intermediate hosts (NMRI-mice, albino rats, Meriones unguiculatus, golden hamsters, guinea pigs, Mastomys natalensis, field-voles [Microtus arvalis], pigeons, and chickens). Only in rats were muscle-cysts formed. The optimal dose was 150 sporocysts per rat. Two generations of merogony could be observed, the first about the 6th day, the second about the 16th day post infection. In the skeletal muscles metrocytes were seen in the young cysts initially, and from the 40th day post infection cystozoites were present. The full grown muscle-cysts measured 1226 x 184 micrometer. They were chambered and possessed a 9.6 micrometer broad stable bristle layer. Older cysts (100 days post infection and more) had shorter processes. To demonstrate the complete life-cycle we fed cyst-containing rat muscles to four reticulated pythons. On the 8th and 13th post infection the feces for 73 to 117 days. Histologic examination of surgically removed parts of the midgut showed that gamogony and sporogony take place in the duodenum and the anterior third of the midgut. Oocysts with sporoblasts were first seen on the 4th day post infection.