noun, plural: endoparasites
(parasitology) A parasite that lives within the body of the host
Parasitism is s form of symbiosis in which one organism (called parasite) benefits at the expense of another organism usually of different species (called host). This host-parasite association may eventuate to the injury of the host. Parasites may be grouped into ectoparasites and endoparasites. Parasites that live outside the host are called ectoparasites whereas those that live inside the host are called endoparasites.
Endoparasites are of two forms: intercellular parasites and intracellular parasites. Intercellular parasites are those that inhabit the spaces of the body of the host. Intercellular parasites are endoparasites that live within the cell of the host. Examples of intercellular parasites are nematodes, tapeworms, and other helminthes. Helminthes live in the gut of their hosts. Examples of intracellular parasites are the protozoan Plasmodium, the causative agent of malaria. They thrive inside the cells of their human host. Plasmodium species have different stages in their life cycle. Within the definitive host (human), the sporozoite stage of Plasmodium species occurs within the liver cells where the sporozoite gives rise to a merozoite or to a hyponozoite, which then infects the red blood cell of the host.
Word origin: Latin parasitus from Greek parasitos (person who eats at the table of another).