Do worms have 9 hearts?
Sarah Duran
Updated on February 20, 2026
Earthworm. Depending on how you define your terms, earthworms either have five hearts, or no heart at all. While they lack the chambered, muscular organ that normally comes to mind, they do have five special blood vessels, called aortic arches, that contract in order to pump blood through the worm's body.
Do Worms have nine hearts?
Earthworms can have five, 10 or zero hearts, depending on how you define "heart." They have five pairs of aortic arches that run along the length of its body (or 10 single arches, if you count each pair as two separate structures).How many hearts do a worm have?
Heartbeats: Worms don't have just one heart. They have FIVE! But their hearts and circulatory system aren't as complicated as ours -- maybe because their blood doesn't have to go to so many body parts. Moving around: Worms have two kinds of muscles beneath their skin.Does a worm have 13 hearts?
EarthwormsThe earthworm can't take heart, because it doesn't have one. Instead, the worm has five pseudohearts that wrap around its esophagus. These pseudohearts don't pump blood, but rather they squeeze vessels to help circulate blood throughout the worm's body, Moore said.