Endogenous stages of Eimeria sigmodontis (Protozoa: Eimeriidae) in the cotton rat, Sigmodon hispidus

Endogenous stages of Eimeria sigmodontis were studied in experimentally infected cotton rats, Sigmodon hispidus. The parasites were located in mucosal epithelial cells of the cecum and colon. E. sigmodontis had a typical coccidian endogenous cycle that consisted of three asexual schizogonous stages and sexual stages composed of the macrogametes and microgametes. The first-, second-, and third-generation schizonts contained 10–17, 5–8 and 10–21 merozoites, respectively. Only one type of wall-forming body was present in the macrogamete. The microgametocyte had a monocentric type of development.