Merozoites

Merozoites, stages in the life cycle of Sporozoa. A merozoite is formed as a result of asexual reproduction of a schizont. In the schizont, the nucleus divides several times in succession without division of the plasma. The daughter nuclei are distributed throughout the cell, then multiple division occurs, resulting in the formation of as many M. as there were nuclei in the schizont. The number of M. formed varies in different species (Plasmodium vivax-15-20, Plasmodium malariae-6-12, in coccidia-up to 200-350).-A M. consists of a portion of plasma with one nucleus. Their form is worm-like (in coccidia) or amoeboid (in malaria parasites and other Haemosporidia). Usually, only the peripheral plasma is involved in the schizont's disintegration into M., while its central portion forms a residual body. After the schizont disintegrates into M., the latter usually penetrate into host cells (into epithelial cells-in coccidia, into erythrocytes-in Haemosporidia) and there develop into schizonts, which again disintegrate into M. by the method described. The cycle of asexual reproduction is repeated several times.-Asexual reproduction is sometimes interrupted by sexual reproduction. In this case, as merozoites grow, they differentiate into sexual cells-macrogametocytes and microgametocytes.