An amebocyte or amoebocyte is a mobile cell (moving like an amoeba) in the body of invertebrates such as echinoderms, mollusks, tunicates or sponges. They move by pseudopodia. Similarly to some of the white blood cells of vertebrates, in many species amebocytes are found in the blood or body fluid and play a role in the defense of the organism against pathogens. Depending on the species, it may also digest and distribute food, dispose of wastes, form skeletal fibers, fight infections, and change into other cell types.