Electron‐Microscopic Studies on Theileria ovis Rodhain, 1916: Development of Kinetes in the Gut of the Vector Tick, Rhipicephalus evertsi evertsi Neumann, 1897, and Their Transformation Within Cells of the Salivary Glands

Gamogony of Theileria ovis Rodhain occurs within the gut of nymphs of the tick Rhipicephalus evertsi evertsi Neumann. After molting, spherical and ovoid parasites are found within the intestinal cells of the ticks. These stages are thought to be zygotes, because they undergo a transformation process leading ultimately (in 3 days) to the formation of a motile stage, the kinete, the fine structure of which is very similar to that of the ookinetes of the hemosporidia. The kinete leaves the gut cells of the tick and penetrates the salivary gland cells where it produces infective stages (the sporozoites). These stages may be transmitted to sheep during the next blood meal of the tick. The developmental processes of T. ovis are compared to those of Hemosporina.