World Octopus Day is celebrated annually on Oct. 8 to appreciate the presence of one of the most distinctive creatures on the planet. Octopus, known to have 8 appendages, is believed to be one of the earth’s great survivors.

Despite their short lifespan, octopus fossils date back more than 300 million years,  pre-dating even dinosaurs. Here are some interesting facts about octopus, whose scientific name is Octopoda.

1. There are more than 250 species of octopus that exist.

2. Octopuses have three hearts – one heart pumps blood between its organs through the body while the other two pump blood through every one of the two gills.

3. Aristotle thought octopuses were dumb and in the History of Animals, written in 350 BC, he wrote: ”The octopus is a stupid creature, for it will approach a man’s hand if it be lowered in the water; but it is neat and thrifty in its habits: that is, it lays up stores in its nest, and, after eating up all that is eatable, it ejects the shells and sheaths of crabs and shell-fish, and the skeletons of little fishes.” After describing a few more quirks of an octopus life history–it ejects ink for self-defense, it’s slimy, it can crawl on land–he flippantly signs off, “So much for the Mollusca.” 

4. They are classed under ‘Cephalopoda’ alongside squids, nautiloids, and cuttlefish.

5. The male octopus dies within a few months after mating.

6. The body of the octopus moves as the octopus breathes.

7. Octopuses have blue blood.

8. Octopus arms have a mind of their own as two-thirds of an octopus’ neurons reside in its arms, and not in the head.

9. Octopuses living in difficult conditions become pretty stressed out, one study found. And, in some cases, they develop a disturbing behavior known as autophagy or eating their own appendages.

10. An octopus is a master of camouflage and can change the color of its body in just three-tenths of a second. octopus An octopus swims at the Ocearium in Le Croisic, western France, Dec. 6, 2016. Photo: LOIC VENANCE/AFP/Getty Images