Giant Pacific Octopus Has 3 Hearts 9 Brains Blue Blood: Fact Check

Story:

The largest octopus species in the world, the giant Pacific octopus, has three hearts, nine brains, and blue blood.

Fact Check:

The message states the largest octopus species in the world, the Giant Pacific Octopus has 3 Hearts 9 Brains Blue Blood. In fact, the message is often shared online as an unbelievable fact. As explained below, the claim is partially hoax.

Octopuses Have 3 Hearts and Blue Blood

Octopuses are fascinating, mysterious and creepy creatures of the sea. Not just the Giant Pacific Octopus, even an ordinary Octopus has 3 Hearts and Blue color Blood. Octopus has a closed circulatory system, i.e. the blood formed remains inside the blood vessels. While the systemic heart circulates blood round the body, the two other branchial hearts pump the blood through each of its two gills. Notably, the systemic heart is inactive when the octopus swims – reason why it tires quickly and prefers to crawl.

Octopuses are deep ocean creatures, where water temperature is very low and not much oxygen is available. To survive in such conditions, invertebrate Octopuses have evolved with Copper-based blood (instead of iron-based blood) called Hemocyanin, which turns its blood blue.

Image of Octopus, an intelligent invertebrate with 8 highly flexible arms. — Octopus, an intelligent invertebrate with 8 highly flexible arms.

Does an Octopus Have 9 Brains?

Octopus has one central Brain and has evolved with large nervous systems and cognitive complexity. However, the central brain is integrated with large optic lobes and the peripheral nervous system (PNS) of its eight arms (tentacles). Octopuses contain large neuron numbers comparable to those of mammals and exhibit complex behavior. Notably, majority of the neurons are present in the arms of the octopus. As a matter of fact, the eight octopus arms have their own sensors and controllers and can work independently without input from the brain. Like for example, they can touch, taste and also control basic motions independently. Their skin itself senses light and responds.

For the aforementioned reasons, it is said the eight highly flexible octopus arms (tentacles) have “minds” of their own. That is why the reference octopus has 9 brains. The central brain and nervous system coordination of the intelligent invertebrate is described in detail in this study.