CRYPTOSPORIDIUM SP OF THE STARRED LIZARD AGAMA-STELLIO - ULTRASTRUCTURE AND LIFE-CYCLE

The life cycle of Cryptosporidium sp. in the gut of its reptilian host Agama stellio was studied by electron microscopy. The parasite was located in a parasitophorous vacuole formed at the microvillous surface of the gut epithelium and was separated from the host-cell cytoplasm by a microfibrillar mesh and a dark band. One type of merogony was observed that produced eight merozoites. The microgamete lacked a flagellum and possessed a unique, anterior adhesive zone. The macrogamete had two types of wall-forming bodies corresponding to those of other coccidia. Sporulated oocysts possessed either a thick or a thin wall. Oocysts were similar in size to those of Cryptosporidium in other reptiles, including another agamed species, and the different life-cycle stages conformed ultrastructurally with those of isolates found in mammals and birds. This is the first detailed electron microscopic study of Cryptosporidium in a reptile. © 1990 Springer-Verlag.