Scientists Say: Parasite

These organisms benefit while their hosts suffer

860-header-parasite.gif

This is a tapeworm in a person’s gut. It’s attached itself to the gut wall and will feed off the food the person eats — making it a parasite.

selvanegra/iStockPhoto

Parasite (noun, “PAIR-ah-syt”)

This is an organism that lives on or in another organism known as a host. Parasites are terrible guests. A parasite benefits from its host, but the host suffers. The relationship is called parasitism.

Parasites can feed off the food a host eats, bite a host for food or burrow inside a host to lay their eggs. This causes harm to the hosts — they can’t get as much food or suffer from itchy bug bites, for instance, and might become sick.

Parasites that live inside a host — such as hookworms and ringworms — are called endoparasites (“endo” is from Greek and means “inside”). Parasites such as lice and fleas that live outside a host are called ectoparasites (“ecto” is also Greek and means “outside”).

In a sentence

Parasites living inside a seal pup’s poop are so delicious that gulls will bite the babies in the butt to get at them.

Check out the full list of Scientists Say here

Bethany Brookshire was a longtime staff writer at Science News Explores and is the author of the book Pests: How Humans Create Animal Villains. She has a Ph.D. in physiology and pharmacology and likes to write about neuroscience, biology, climate and more. She thinks Porgs are an invasive species.

More Stories from Science News Explores on Health & Medicine