Octopuses have three hearts: two pump blood through the gills, one pumps oxygenated blood to the body. Learn why they have blue blood and why their heart stops when they swim.
Three hearts, blue blood, and a main heart that stops every time they swim - an octopus operates like a creature from another planet. Here is the breakdown of how their incredible body works.
An octopus doesn't just have "extra" hearts; each one has a specific job to do:
The main heart of an octopus is actually quite sensitive. When an octopus swims by "jetting" (blasting water to move fast), the pressure inside its body increases, causing the systemic heart to stop beating. Because this is very exhausting, octopuses prefer to crawl along the ocean floor rather than swim.
Unlike humans, who have red blood because of iron-based hemoglobin, octopuses have blue blood. They use a copper-based protein called hemocyanin to carry oxygen.
Living in the deep, cold ocean is tough. Having two hearts dedicated just to the gills ensures that the octopus can grab every bit of oxygen possible from the water. The three-heart system provides the high blood pressure needed to fuel their large, complex brains and active lifestyles.
Octopuses have a unique three-heart system: two for the gills and one for the body. Their blood is blue because it uses copper instead of iron to carry oxygen. Because their main heart stops when they swim, they are the marathon walkers - not swimmers - of the sea.