Five true, tentacle-tingling facts about the ocean's cleverest shapeshifter — then a quick quiz to see if you were paying attention.
Made for Jordan 🌊Two "branchial" hearts pump blood through the gills to pick up oxygen, while a third "systemic" heart sends it around the body. The systemic heart actually stops beating while the octopus swims — which is one reason many octopuses prefer to crawl.
Instead of iron-based hemoglobin like ours, octopuses use a copper-based protein called hemocyanin to carry oxygen. Copper turns the blood blue and moves oxygen efficiently in the cold, low-oxygen water octopuses often live in.
An octopus has around 500 million neurons, and about two-thirds of them are spread through its eight arms rather than its central brain. Each arm can taste, feel, and react on its own — earning octopuses a reputation for having "nine brains."
Octopuses have only one type of visual pigment, so they're effectively colorblind. Yet using nerve-controlled skin cells called chromatophores, they can change color and pattern in milliseconds to blend into almost any background.
With no bones at all, an octopus's only hard part is its parrot-like beak. As a rule of thumb, if the beak fits through an opening, the whole octopus can follow — letting even large octopuses slip through a hole barely an inch wide.
Three questions, all answerable from the facts above. Pick an answer for each, then hit Check my answers.