Featured Image Credit: Albert Kok via Wikipedia
Let’s face it, octopuses are probably the most interesting creatures in the entire ocean. Aside from the fact that they can problem solve, squeeze through impossibly small holes, change colors, lay 20,0000-100,000 eggs… okay, we can go on and on…
But let’s talk about the coolest fact of all…that octopuses have THREE freaking hearts. Not one, not two, but three.
Their circulatory system is one of the most interesting in all cephalopods. Unlike other mollusks, they have a closed circulatory system, which means all of their blood remains inside their blood vessels. Having multiple hearts isn’t as odd as it might seem, though. Octopuses have a systematic heart and two branchial hearts that each have a specific job to do.
The two branchial hearts sit right behind the octopuses eyes and are connected to its gills, where oxygen gets into its blood. From there, that blood goes to the systematic heart located in the octopuses center which pumps oxygen-rich blood to the rest of the body.
If you think about it, when you have eight legs, it’s probably necessary to have more than one heart.
Octopus blood also contains the copper-rich protein hemocyanin to transport oxygen. This makes the blood very thick and viscous, which requires considerable pressure to pump it around the entire body.
There are hundreds of species of octopuses, ranging in size from less than an inch long to more than 30 feet. Even within species, octopuses are constantly changing their image. With special cells called chromatophores, they can change colors instantly to reflect their mood or to blend in with their surroundings.
Camouflage comes in handy when they get hungry, but so do their tentacles. Many species have toxic venom in their tentacles that they use to kill shrimp, lobsters, crabs, snails and other prey.
With all that blood flow, plus a big, smart brain, a squishy body and fine-tuned senses, octopus are able to act fast to get in and out of tight spots. Pretty sick, huh?