Endoparasites utilize blood as a food by ingesting it whole or absorbing nutrients from it.
The blood flukes such as Schistosoma live within the bloodstream and ingest whole blood through their mouth.
Trypanosomes swim freely in the blood, absorbing its molecular constituents.
Malarial organisms such as Plasmodium live an intracellular existence, absorbing molecules from within erythrocytes.
Hookworms, which live in the lumen of the intestine, use cutting plates in their buccal cavities (B) to embed their anterior ends within the intestinal mucosa (M). The esophagus (E) then pumps blood directly from damaged vessels.
Liver flukes such as Fasciola migrate through the liver during their early development, ingesting blood through the mouth (M), past the pharynx (P) and into the elaborate intestinal ceca (C) where it is digested. Undigestible material is regurgitated.
Entamoeba histolytica usually lives in the intestinal lumen but can cause ulcers and enter the tissues. There it can feed on blod cells by pinocytosing them.
