Abstract
The life cycle of Hepatozoon hemprichi n. sp. is described; the vertebrate host is Scincus hemprichii and it is vectored by Hyalomma impeltatum. Erythrocytic stages of 18 +/- 1.8 x 4 +/- 0.8 mu m developed in the hemocoel of ticks to sporozoites within 16-18 days. Schizogony occurred in the liver parenchyma and the endothelial cells of blood capillaries in lung and spleen. Mature schizonts measuring 27 +/- 3.11 x 20.13 +/- 3.0 mu m produced 28 merozoites (on average). The merozoites were 13 +/- 1.21 x 1.21 +/- 0.72 mu m with nuclei 5 +/- 0.65 x 2.1 +/- 0.51 mu m. Syzygy and differentiation of gamonts took place in tick's hemocoel up to the third day post-infection (PI). The microgamont (16 +/- 0.31 x 18 +/- 0.42 mu m) produced 4, uniflagellated microgametes at 4-5 days PI. The microgamete measured 15.2 +/- 0.31 mu m while the flagellum was always at least 26 mu m. The macrogamete was very large in size (31 +/- 3.11 mu m) with a central nucleus. After fertilization, (5-6 days PI) zygotes developed into oocysts (55 +/- 3.41 x 52 +/- 4.11 mu m) in which repeated mitotic divisions with centripetal invaginations occurred; each contained 18 banana-shaped sporozoites, 13.61 +/- 0.8 x 1.2 +/- 0.31 mu m in size. Experimental transmission was successfully carried out by oral administration or by intra-peritoneal inoculation of the infective stages (sporozoites) to uninfected skinks and led to the appearance of blood stages after 5 wk and 4 wk, respectively.