Sarcocystis sp. from white-fronted goose (Anser albifrons): cyst morphology and life cycle studies.

An experiment was carried out using three cubs of the arctic fox (Alopex lagopus). Twenty-five-day-old cubs were infected by feeding them with the leg muscles of the white-fronted goose (Anser albifrons) containing Sarcocystis sp. (cyst type III) cysts. Under the light microscope, the cysts were ribbon-shaped up to 4 mm long and up to 750 microm wide. On the surface of the wall (up to 2.4 microm), they had teat- or finger-like villar protrusions. Ultrastructurally, the cyst wall was a type-9 with villar protrusions (up to 2.3 microm long) different in size. The 11.4x1.7 (10.0-13.5x1.5-2.5)microm cystozoites were almost straight and shuttle-shaped. The fox cubs started shedding typical 12.0x8.0 (10.0-12.8x6.8-8.6)microm Sarcocystis sp. sporocysts on the 13th-14th days post-infection. The patent period lasted 19 days. The conclusion drawn was that the arctic fox (A. lagopus) can be one of the definitive hosts of Sarcocystis sp. (cyst type III) from the white-fronted goose.