Studies on Eimeria species naturally infecting Gerbillus pyramidum (1) Exogenous stages

Exogenous stages of two new Eimerian species, naturally infecting the Egyptian gerbil Gerbillus pyramidum were described and diagnosed in the present study. (1) The subspherical type of oocysts was 20 x 17 microns (length x width) in average. These are colourless and enveloped within an even double-layered oocyst wall. Sporulated oocysts containing four sporocysts each averaged in 10 x 8 microns, and a small spherical oocyst residual body was also observed. This type is termed Eimeria pyramidi after the species name of its host. (2) The second type of oocysts was elongated in shape measured congruent to 21 x 16 microns. These are colourless and enclosed within smooth double layered oocyst wall. Sporulated oocysts of this type were lacking oocyst residual bodies. This type is termed Eimeria gerbilli after the generic name of its host. Both types of described oocysts lack micropyle and polar cap.