Octopuses have three hearts and blue blood; two hearts pump blood to the gills while the third pumps it to the rest of the body.
Notes on verification
Standard marine biology fact, documented in countless zoology textbooks and scientific literature [2026-08-28 re-verified orphan: promoted with 4 independent source(s)] [2026-08-29 audit re-verified: 5 independent source(s)]
Sources
- https://medium.com/the-shortform/meet-the-octopus-the-creature-with-three-hearts-and-blue-blood-465ab3bdbf9e (reverify-primary)
- https://www.britannica.com/science/How-Many-Hearts-Does-an-Octopus-Have (corroboration)
- https://www.msn.com/en-us/science/biology/octopuses-have-three-hearts-and-blue-copper-based-blood/ar-AA2a1tbD (corroboration)
- https://spacedaily.com/t-octopuses-have-three-hearts-and-blue-blood-that-carries-oxygen-using-a-copper-based-protein-rather-than-iron-and-because-the-heart-that-supplies-the-body-stops-beating-whenever-they-swim-many-bottom/ (corroboration)
- https://wowtoknow.com/octopuses-have-three-hearts-and-blue-blood/ (corroboration)
- https://www.smithsonianmag.com/science-nature/ten-wild-facts-about-octopuses-they-have-three-hearts-big-brains-and-blue-blood-7625828/ (audit-corroboration)
- https://octonation.com/how-many-hearts-does-an-octopus-have/ (audit-corroboration)
- https://www.nhm.ac.uk/discover/octopuses-keep-surprising-us-here-are-eight-examples-how.html (corroboration)
- https://study.com/academy/lesson/the-octopus-circulatory-system.html (audit-corroboration)