Useless Factsanimals
Octopuses have 3 hearts, and 2 stop beating when they swim
🤷 This changes nothingFact Battle
An octopus has one main heart (the systemic heart) that pumps blood to the body, and two branchial hearts that pump blood through each gill. When an octopus swims by jet propulsion, the branchial hearts stop contracting — which is why octopuses prefer crawling and tire quickly when swimming. Their blue blood contains copper-based hemocyanin instead of iron-based hemoglobin.
Why this is surprising
Most people don't know octopuses have three hearts, let alone that swimming literally stops two of them from beating.
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“Octopuses have 3 hearts. When they swim, 2 of them stop beating — which is why they tire so easily. Also: blue blood. 🐙 #OddlyHuman”
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