Class Actinopoda This class contains two orders, Heliozoa and Radiolaria, which are superficially rather similar. Individuals of both orders may have siliceous skeletons arranged as spheres with holes in them. Axopodia, pseudopodia stiffened with axial filaments, project through the holes. Food is caught on the axopodia and is drawn by the movement of the cytoplasm … Read more
Rhizopods (Class Rhizopoda) This class includes the various species of amoebas. Typically amoebas crawl on the surface of the mud, submerged plants, in the spaces between soil particles, or inside animals as parasites. Locomotion is by means of pseudopodia, which may be long and thin but usually unbranched (filopodia), long, thin, and branched, uniting with … Read more
Zoomasts (Subclass Zoomastigina) These are flagella-bearing protozoans which have truly animal methods of nutrition. Many are parasitic and have been extensively studied as they affect the life of man. The number of free-living species is not certain. They are morphologically diverse and are best considered in their orders. Protomonads (Order Protomonadina) All members have only … Read more
The flagellates (Class Mastigophora) This class contains organisms which are actively motile by means of flagella. They may have a single flagellum or they may have hundreds, so that they bear a strong superficial resemblance to dilates. The nuclei are usually restricted to one per cell but if there is more than one they are … Read more
Phylum Protozoa (PROTOZOANS) The term Protozoa embraces the vast assemblage of living organisms, some free-living, some parasitic, that appear to organize their whole lives as single cells. Estimates of the total number of species are difficult to make because the definition of the term species is particularly unclear in the Protozoa. It is safe to … Read more