A genus of parasitic protozoans that infect birds, reptiles, and herbivorous mammals. S. lindemanni, which occasionally infects man, forms cylindrical cysts (sarcocysts) in the muscle fibers. In heavy infections these cysts can cause tissue degeneration and so provoke muscular pain and weakness. Sarcocysts have, in the few positively diagnosed cases, been located in the heart muscles, arm muscles, and larynx.
A genus of sporozoa found in the muscles of higher vertebrates (reptiles, birds, and mammals).