How Many Hearts Does A Mosquito Have

How Many Hearts Does A Mosquito Have

Mosquitoes have a very different way of getting oxygen to their organs than mammals; in fact, they don’t have blood vessels. Instead, a mosquito’s heart pumps a fluid known as hemolymph, which serves a similar purpose.

The hemolymph is a fluid plasma filled with cells called hemocytes that carry oxygen and nutrients instead of red and white blood cells. How many hearts does a mosquito have?

A mosquito has only one heart that takes up around two-thirds of their circulatory system. These tiny insects have a unique configuration where the dorsal vessel is divided into a thoracic aorta and an abdominal heart. However, the unusual spread-out parts of a mosquito’s heart work incredibly well together, providing oxygen and nutrients to its body.

Does Mosquito Have Heart

If you had only ever seen mammal hearts and then dissected a mosquito, it would be very easy to assume that mosquitoes have no heart.

Moreover, you wouldn’t find a vascular system. The whole insect would seem like a confusing mess because its biology is different. However, mosquitoes do have a heart.

It would be difficult to evolve a working mammalian-style heart and blood vessels when you are as small as a mosquito.

The system works for more giant creatures because our bodies are set up with bones and marrow that insects lack.

As Medline Plus explains, “Stem cells in the red bone marrow are called hemocytoblasts. They give rise to all of the formed elements in the blood. If a stem cell commits to becoming a cell called a proerythroblast, it will develop into a new red blood cell. The formation of a red blood cell takes about two days.”

Insects can’t make blood cells, so they evolved a different way to get nutrients and oxygen to their other cells. However, they still need the heart to pump their blood substitute.

Structure Of Mosquito Heart

Like a human, mosquitoes have a four-chambered heart that pumps, but that’s about all they have in common. A dorsal vessel runs the entire length of these tiny insects.

Meanwhile, the heart is divided into two parts, the thoracic aorta located, predictably, in the thorax, and the abdominal heart lower down in this abdomen.

The heart itself is elongated and has numerous Ostia or holes for the fluid to exit from along the length.

The mosquito heart pumps hemolymph into the body cavity, which eventually circulates and returns to be pumped again.

More interestingly, a mosquito’s heart switches directions pumping fluid both ways to get it circulating. If you want to see a mosquito heart for yourself, I recommend this video from CNN.

Can A Mosquito Have A Heart Attack

There are no recorded instances of mosquitoes having heart attacks. We associate mosquitoes with speed, but that doesn’t mean their hearts are racing under extra stress.

Typically, a mosquito’s heart beats at 1.37 Hz or eighty-two beats per minute, which is in the same range as a human adult.

Humans usually have heart attacks because of their health. Lack of physical activity and a bad diet can lead to blocked arteries which cause the heart to fail.

Mosquitoes don’t have issues with inactivity or a bad diet.

However, it could technically be possible for a mosquito’s heart to have a heart-attack-like issue. If a blockage formed, the heart would cease up.

So, while no known mosquito has ever had a heart attack, and they are not at high risk of them, a mosquito could have a heart attack simply because it has a heart.

Does Mosquito Have 2 Hearts

Some people mistakenly believe a mosquito has two hearts or more. Two would be a stretch, but at least that’s a little bit believable since we associate these insects with speed.

Having two hearts would be a significant advantage if mosquitoes had a vascular network like mammals. However, they do not.

However, since these insects don’t have blood or blood vessels as we see in mammals, birds, amphibians, and reptiles there’s no need for an extra heart to handle the blood.

A segmented heart, which mosquitoes do have, is not the same as having two or more entire hearts in your body.

Additionally, there’s probably some confusion because a mosquito’s heart reverses direction and pumps both ways. Mosquito hearts are incredible and complex, but they each only have one.

The confusion about multiple hearts probably comes from the configuration. After all, most people aren’t doctors or biologists.

It is easy to misread something as complex as a segmented heart and think the separate parts are organs on their own.

A mosquito’s heart has a dorsal vessel subdivided into an abdominal heart and a thoracic aorta, however, these are all part of the same extended organ.

Does Mosquito Have 3 Hearts

If mosquitoes only have one heart, like other insects and animals on earth, why do people believe it has three? I dug around on this rumor for a while and came up with almost no explanation at all.

After an embarrassingly long hunt, I realized that the simple solution to this bizarre mistaken belief was staring me right in the face on page one of Google’s results.

A couple of contributors on a Reddit thread said it was true. One claims they read it in a book, and the other says it was proved by scientists in Switzerland.

A comment on that comment points out that octopuses have three hearts, which is true, but only marginally relevant.

Because there were so few answers to the question the results come back showing both of the yes answers.

Casual searchers who only scanned the google results without reading further would have accepted that some people said mosquitoes have three hearts and then passed it along to others as a ‘fact’ that they looked up.

This is a case of ‘don’t believe everything you read on the internet.’ Also, it’s a great reminder that you should always read the whole article.

Helpful Tips To Know About How Many Hearts Does A Mosquito Have

Mosquitoes only have a single heart, though it is set up very differently from human hearts, which causes some confusion. More importantly, the tiny mosquito has no need for a second heart since it doesn’t pump blood around its body.

  • A mosquito’s heart is two-thirds of its entire circulatory system. Unlike non-insects, mosquitos lack an extensive vascular system. Instead, their heart pumps hemolymph directly into the body cavity.
  • There are no insects on earth with multiple hearts. Every type of bug, including the mosquitoes, have a single heart apiece even when those hearts are spread out differently from mammal hearts. The advantage to not needing a circulatory system like other animals is that your heart can be configured differently.
  • When female mosquitoes fill up on blood to provide much-needed protein to their eggs, it goes to their stomach, not their body. Incidentally, this is the only time a mosquito has blood in it’s body. These insects have a blood-like substance called hemolymph that surrounds their organs and fills in the spaces inside their body instead of using blood vessels and a mammalian circulatory system.

Final Thoughts

Some people will be disappointed to learn that a mosquito only has one heart. However, when you look at the bizarre and incredible features of a mosquito heart, it’s hard not to be impressed.

For such a simple organ, this heart is incredibly efficient at its job. Since mosquitoes only need to pump hemolymph around their body cavity, they do not need a more complex heart.

More importantly, having more than one heart wouldn’t help a mosquito do anything.

Ted Smith

My name is Ted Smith and I’m the creator of AnimalThrill.com. I have a passion for educating people about animals and wildlife. I have been working with the National Wildlife Federation for the past 10 years and I became a wildlife blogger to help people become excited about animals and encouraged to care for these wonderful creatures.

Recent Posts