A light microscopic study on the haemogregarine species infecting the lizard Acanthodactylus schmidti from Saudi Arabia.

Eleven out of 42 (26.2%) lizards Acanthodactylus schmidti were found harboring haemogregarines in their peripheral blood. The erythrocytic stages were differentiated into 2 forms: the young form (trophozoite) measured 12.5 +/- 0.5 x 1.7 +/- 0.3 microm and the large mature form (gametocyte) measured 19.8 +/- 1.7 x 1.7 +/- 0.3 microm. The infected erythrocytes were distorted from 16.0 +/- 1.2 x 9.2 +/- 0.2 microm to 20.2 +/- 1.8 x 6.7 +/- 0.8 microm, hypertrophied and faintly stained. None of the leucocytes seemed to be parasitized by the present parasite. Schizogony took place in the endothelial cells of lung capillaries and parenchyma of liver. Two types of schizonts were recorded; microschizonts of 9.35 x 9.65 +/- 0.38 microm and macroschizonts of 25.36 +/-1.81 x 20.35 +/- 0.82 microm. The microschizonts produced 6-12 merozoites, while the macroschizonts produced 18-36 merozoites, however there were no differences between both merozoites, each measured 11.54 +/- 0.81 x 1.41 +/- 0.71 microm. The infected host cells were markedly hypertrophied with noticeable irregularity and faint stainability as well as some vacuolation, necrosis or shrinkage and necrosis.