Octopuses have three hearts: two branchial hearts that pump deoxygenated blood through the gills, and one systemic heart that pumps oxygenated blood to the rest of the body — and the systemic heart stops beating entirely while the animal swims, which is why octopuses prefer crawling.
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What we found
Does an octopus really have three hearts? Yes, and one of them stops beating when it swims.
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Transcript
An octopus has three hearts — and one of them shuts down every time it swims. Two smaller hearts, one on each side, push blood through the gills to pick up oxygen. A third, larger heart then pumps that oxygenated blood to the rest of the body — the organs, the arms, the brain. But the moment an octopus starts swimming, that main central heart stops beating entirely. The animal is essentially running on partial circulation, which is exhausting. That is why octopuses almost always prefer to crawl along the seafloor rather than swim — swimming literally makes their heart stop. Next time you feel winded after exercise, at least your heart kept going. Follow for a fact every day.
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