Why Octopuses Have Three Hearts – and What They Do

If one broken heart feels like the end of the world, imagine having three.

That’s not a cheesy breakup line — it’s just daily life for an octopus.

These mysterious sea creatures are full of surprises: they can change color, squeeze through tiny spaces, and even solve puzzles.

But one of the most bizarre facts about octopuses?

They have three hearts — and each one plays a different role.

Let’s dive into the anatomy of this alien-like genius from the deep.

The Three Hearts – What They Do

Octopuses have three hearts for a reason — and it's all about survival under the sea.

1. Two branchial hearts

These pump blood to the octopus’s gills, where it gets oxygen.

Each branchial heart works for one gill. They’re like the delivery team — collecting “dirty” blood and sending it off for oxygen refill.

2. One systemic heart

This is the main heart. Once the gills give the blood fresh oxygen, the systemic heart pumps it to the rest of the body — to fuel the arms, brain, and muscles.

Sounds efficient, right? But here’s the weird twist:

When an octopus swims, the systemic heart stops beating.

That means octopuses get tired very quickly — which is why they prefer crawling over swimming.

Yup, even sea creatures hate cardio.

Why Is Their Blood Blue?

Octopuses have blue blood — and that’s not just for drama.

Unlike humans (who use iron-based hemoglobin), octopuses use copper-based hemocyanin to carry oxygen.

Copper works better than iron in cold, low-oxygen environments like the deep ocean.

That’s why their blood is literally blue — and why three hearts are needed to keep the thick, sluggish blood flowing.

So while it looks alien to us, it’s perfect for octopus life.

A Brain to Match the Hearts

A creature with three hearts deserves a smart brain, right?

Well, the octopus has nine brains — sort of.

• One central brain that handles main thinking and decision-making.

• Eight mini brains, one in each arm, that control movement independently.

This makes octopuses unbelievably intelligent — they can:

• Open jars

• Solve mazes

• Escape tanks

• Use tools

Some scientists even believe they dream when they sleep — and can recognize human faces.

Evolution at Its Strangest

Why would nature design a creature this way?

Octopuses evolved in harsh, high-pressure environments, where being smart and flexible was key to survival.

Having:

• Blue blood helps them breathe deep underwater.

• Three hearts keep that blood flowing.

• Eight arms help them multitask.

• Nine brains let them control it all like a supercomputer.

Basically, the octopus is like a sci-fi character that accidentally ended up in the ocean instead of outer space.

Final Thought

Octopuses break all the rules of biology — and they don’t even care.

They’re soft, squishy, and silent… but inside, they carry more power than most creatures twice their size.

Three hearts.

Nine brains.

Eight arms.

Blue blood.

It sounds made up — but it’s all real.

They remind us that nature isn’t boring. It’s bizarre, brilliant, and full of secrets.

We often think of humans as the smartest or most evolved species — but creatures like the octopus quietly challenge that.

They don't build cities or write books, but they do something more magical:

they live by instincts so complex, so deeply connected to their environment, that science is still catching up.

Octopuses also remind us of something deeper — that survival doesn’t always mean being the strongest.

Sometimes, it means being the most adaptable, the most curious, the most unexpected.

In a world that often celebrates speed and flash, the octopus thrives with silence, mystery, and slow-moving brilliance.

So maybe having three hearts isn’t just about pumping blood —

maybe it’s a sign that feeling and adapting are just as important as thinking and reacting.

And maybe, just maybe — being a little weird is a superpower after all.