Q.Parasites that feed on the external surface of the host organism are called ____________.

Types of Parasites (Ectoparasites and Endoparasites)

A parasite is an organism that lives on or in another organism (the host), taking food and shelter from it while harming it. But parasites differ in one obvious way: some live on the outside of the host, and others live inside it. This single question — outside or inside — gives us the two main categories.

Ectoparasites — living on the surface

Ectoparasites live on the external body surface of the host and feed from there. The prefix ecto- means "outside". They usually feed on skin, blood or hair.

Examples:

• Lice on the human scalp and body.
• Ticks and mites on the skin of animals.
• Leeches that attach to the skin to suck blood.
• The plant parasite Cuscuta (dodder), which grows over a host plant's surface.

Because they live outside, ectoparasites are exposed to the environment and are often easier to spot and remove.

Endoparasites — living inside

Endoparasites live inside the host's body — in the gut, blood, liver, or other tissues and organs. The prefix endo- means "inside". Life inside a host is a challenge (low oxygen, host defences), so endoparasites often show special adaptations: loss of unnecessary organs, resistance to the host's digestive enzymes, and huge reproductive capacity.

Examples:

• Tapeworm and roundworm (Ascaris) in the intestine.
• Plasmodium (malarial parasite) in the blood and liver.
• Liver fluke in the bile ducts.