How Unsegmented Worms Fit into the World?

Free-living flatworms always form food chain of bigger animals. Some help aerate the soil with their burrows. However, unsegmented worms are generally known as parasites: hookworms, trichinosis-causing worms, filarial worms, eye worms, etc.

• Hookworms are serious human intestinal parasites that are common in tropical countries. Its eggs hatch outside the body of the host and develop in the soil. If they find an unprotected foot, they use sharp teeth and hooks to burrow into the skin and enter the bloodstream. Then these worms travel through blood to lung and then down the throat to the intestines.
• Trichinosis is a terrible disease caused by the roundworm Trichinella. They cause pain as they burrow into the host’s tissue, where they become inactive. Humans get trichinosis exclusively by eating raw or incompletely cooked pork.
• Filarial worms, which are found primarily in tropical regions in Asia, are threadlike worms that live in blood and lymph vessels of mammals like humans. They are transmitted from one primary host to another through biting insects, especially mosquitoes. Large number of this worm may block the passage of fluids within lymph vessels, causing elephantiasis.
• Eye worms live and burrow through the tissues just below the skin of their host. In their travels, the worms occasionally move across the surface of the eye, hence naming eye worms.