Do Worms And Earthworms Have Hearts? (Interesting Facts)

The heart is a crucial part of a living thing’s body but do all animals have hearts? Or better yet, do worms and earthworms gifted with hearts? We will be going to find that out.

So, do worms and earthworms have hearts? Worms and earthworms do have a heart. The amazing thing is that they do not just have one heart; worms and earthworms have five hearts!

Worms and earthworms may be viewed by many as worthless in this world. Some kids would make fun of them, and they are considered to be just a prop in this world. But are they? 

Worms and earthworms do play a very vital role in our ecosystem. Worms are beneficial in gardens, for one. 

They can break down organic matters for the use of plants. The judgments for worms and earthworms came mostly because of their physical appearance. 

When you see worms and earthworms, they are just plain looking, and some are even disgusted and scared by it. Let us get to know more about earthworms and their hearts.

How Many Hearts Do Worms And Earthworms Have?

If you still do not know about it, worms and earthworms do have a heart. But they do not just have one heart. Worms and earthworms have five hearts. 

This would be the tricky part of this question because worms and earthworms can have no heart. They can have five hearts or even ten hearts. Worms and earthworms have five aortic arches. 

These five aortic arches run through the length of the worm’s body. They also have multiple chambers. But all would say that worms and earthworms have five hearts. Worms and earthworms’ hearts are located near their mouth with five pairs. 

The heart of worms functions almost the same as a human heart. The difference is that humans breathe oxygen through the mouth and nose while worms breathe oxygen through their skin. 

For them to breathe, they need to keep their skin moist all the time. If they are dried, they will suffocate and mostly die.

Related Articles About Worms Anatomy:

Why Do Worms And Earthworms Have 5 Hearts?

Worms and earthworms have a closed circulatory system. So worms and earthworms would circulate their blood through vessels. With this, there are three main vessels in a worm’s body. 

The three vessels are aortic arches, dorsal blood vessels, and ventral blood vessels. These aortic arches function as a heart. These aortic arches serve the same as the heart. 

These aortic arches also have their functions. They need to work together to keep a worm alive. These aortic arches transfer the blood and make the blood support the worm’s body. 

Of course, experts do not have a specific answer to why worms have five hearts, but this is the mystery of nature. Worms and earthworms tend to be taken for granted because they are tiny creatures whose purpose in the ecosystem is unknown to all people. 

They have this odd body and a very plain one at that too. Maybe the worms and earthworms need many hearts to support their bodies.

What Do Worm Hearts Look Like?

The worm of a heart looks more like a vein. It is wrapped around the esophagus inside the worm, and it is in pairs. The body of an earthworm has an outer layer. 

Their outer layer has an epidermis and a cuticle or a hard protective covering. Worms and earthworms are full of segments in their body. One type of worm is the segmented worms where its body is made up. 

These segments are made to allow worms to move quickly especially when they are burrowed in soil. The hearts of the worms are located near its mouth. It functions just the same as a human heart. Earthworms have five pairs of aortic arches. 

They are similar to a long vein that is wrapped around the esophagus and form the heart. These aortic arches are sometimes called pseudo hearts. These hearts’ job is to receive blood and pump it to other arches.

Do Worms’ Hearts Have Any Special Function?

The heart of the worm functions almost the same as humans. If an earthworm breathes through its skin, the aortic arches will pump the oxygenated blood through a worm’s body. This oxygen will then be used for its dorsal and ventral blood vessels. 

This blood will then be carried to the head of the worm by dorsal blood vessels. This blood will also be sent back to the worm’s backside by the ventral blood vessels. These aortic arches can be found in the anterior part of the worm. 

These aortic arches also connect the ventral blood vessels and the dorsal blood vessels. This worm’s heart would pump blood into the blood vessels of the worms. Aside from that, aortic arches would also maintain calcium homeostasis. 

The worm’s heart’s primary function is to pump blood through the worm’s heart and supply oxygen all over the worm’s body. The second other function of the worm’s heart is to maintain the homeostasis or the balance of calcium in the worm’s body.

Read also other articles about worms’ blood, lungs, ears, legs and bones.

Can A Worm Survive Without One Heart?

Worms have five hearts, and these five hearts are working together to keep the worms and earthworms alive. If you asked about the survival rate of the worms and earthworms, the answer would most likely die if we remove the other heart. 

These worms and earthworms were living on this earth and were given five hearts to function fully. If we remove the other heart, the balance or homeostasis inside the worm’s body will be triggered. 

If it means cutting the other heart out, the worms and earthworms will not survive the intrusion into their body. The worms need to have all five hearts because each aortic arch has its function.


In summary, worms and earthworms may look like they have no heart, but they have. The shocking thing is that they do not have just one heart but five hearts, for that matter. 

Experts have not found out the reason for it having five hearts, but each has its function. These hearts supply the blood of the worms and maintain the calcium homeostasis inside the worm’s heart.


Image credits – Canva

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