The Clever Octopus

What has three hearts, a big brain, and blue blood?

The octopus, of course!

These bizarre yet brilliant creatures have been around for hundreds of millions of years. For humans, they’ve inspired emotions ranging from curiosity to admiration — and even fear, thanks to their starring roles in Hollywood monster flicks.

Belonging to the class Cephalopoda, octopuses are easily recognised by their soft, flexible bodies, large heads, and eight long tentacles lined with powerful suckers. They are common residents of the Great Barrier Reef, though not often seen — their remarkable camouflage allows them to blend almost perfectly into the reef around them.

Let’s dive into some of the amazing facts that make octopuses such extraordinary animals.

Masters of Disguise

Octopuses are true masters of camouflage. They can change both colour and texture in the blink of an eye using specialised skin cells called chromatophores. These tiny pigment sacs expand or contract to create patterns that mimic rocks, sand, coral, or even other animals. Combined with fine control of their skin texture, they can virtually disappear from sight.

Three Hearts and Blue Blood

Octopuses literally have three hearts. Two of them pump blood through the gills, where it picks up oxygen, while the third heart circulates that oxygen-rich blood to the rest of the body. Interestingly, the main heart stops beating when the octopus swims, which is why these animals prefer crawling over gliding — swimming tires them out quickly!

Their blood is blue, thanks to a copper-based molecule called hemocyanin that carries oxygen more efficiently in cold, low-oxygen environments. However, this adaptation makes octopuses highly sensitive to changes in ocean acidity — a growing concern as climate change continues to alter marine chemistry.

Brainy and Bold

Octopuses are among the most intelligent invertebrates on Earth. With large brains and a complex nervous system, they can solve puzzles, open jars, navigate mazes, and even remember solutions for future use. They also have distinct personalities — some are shy, others curious or mischievous.

A fascinating fact: two-thirds of their neurons are in their arms, not their heads. This allows each arm to operate semi-independently — one might be prying open a shell while another explores a crevice for food. Even detached arms can respond to touch, a remarkable sign of their distributed intelligence.

Inky Defence

When threatened, an octopus releases a dark cloud of ink — but it’s more than just a smokescreen. The ink contains tyrosinase, a compound that irritates predators’ eyes and confuses their sense of smell and taste. This clever chemical weapon gives the octopus precious seconds to vanish.

A Short but Devoted Life

Octopuses live fast and die young. After mating, the male soon dies, and the female devotes herself entirely to her eggs — sometimes up to 400,000 of them. She guards and cleans them constantly, refusing to eat until they hatch. By the time her young are ready to face the world, she is near death. It’s a sad but noble end for such an intelligent and devoted parent.

A True Ocean Genius

The octopus is one of the most fascinating creatures on our planet — an animal of intelligence, adaptability, and mystery. From its three hearts to its shape-shifting skin and problem-solving mind, the octopus truly reigns as a master of its domain.

Contributed with thanks to Whitsunday Conservation Council.

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Octopus. Photo supplied.

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