when it occurs, involves markedly anisogamous gametes. The lifecycle is typically haploid, with the only diploid stage occurring in the zygote, which is normally short-lived.

The main difference between the coccidians and the gregarines is in the gamonts. In the coccidia, these are small, intracellular, and without epimerites or mucrons. In the gregarines, these are large, extracellular, and possess epimerites or mucrons. A second difference between the coccidia and the gregarines also lies in the gamonts.