Imagine running so hard that two of your three hearts suddenly stopped beating.
Sounds impossible.
For an octopus, it's completely normal.
The octopus is one of the most unusual creatures on Earth. Unlike humans and most animals, it doesn't rely on a single heart. Instead, it has three separate hearts, each with a specific job.
One heart pumps blood throughout the body, while the other two send blood to the gills where oxygen is collected.
But here's where things get weird.
When an octopus starts swimming, the two hearts responsible for the gills temporarily stop beating.
Scientists believe this is one reason octopuses often prefer crawling across the ocean floor rather than swimming long distances. Swimming requires significantly more energy and puts extra stress on their circulatory system.
Their Blood Isn't Red
The surprises don't stop there.
Human blood is red because it uses iron-based hemoglobin to transport oxygen.
Octopus blood is blue.
Instead of hemoglobin, octopuses use a copper-based protein called hemocyanin.
This adaptation helps them survive in cold, low-oxygen environments deep beneath the ocean's surface.
Smarter Than Many People Realize
Octopuses are also considered among the most intelligent invertebrates ever studied.
Researchers have observed them:
- Solving puzzles
- Escaping aquariums
- Opening containers
- Using tools
- Recognizing patterns
Some have even learned how to unscrew jar lids from the inside.
That's a remarkable achievement for an animal whose ancestors evolved hundreds of millions of years ago.
A Brain Unlike Ours
What's even more fascinating is that much of an octopus's nervous system isn't concentrated in its brain.
Around two-thirds of its neurons are distributed throughout its arms.
In a sense, each arm can process information and react independently.
This means an octopus arm can continue responding to its environment even when separated from the central brain.
Few animals on Earth operate this way.