The types of protozoa are the sarcodines, the mastigotes, the sarcomastigotes and the apicomplexans. Protozoans are single-celled organisms that have nuclei and act somewhat like animals. Protozoans usually live near sources of water.
The sarcodines, or amoeboids, consist of the amoebas and their relatives. These protozoans move by means of pseudopods, which are projections of their cytoplasm. Pseudopods can also help ameboids feed by surrounding and engulfing a food source. The mastigotes are the flagellates that move using structures called flagella, which are whip-like extensions. The sarcomastigotes, or the ciliates, travel using cilia, which look like tiny hairs that beat back and forth rhythmically. The paramecia are examples of sarcomastigotes. Apicomplexans, historically called the sporozoans, are a subgroup of protozoans consisting only of parasitic species. The plasmodia species that causes malaria is an apicomplexan.