Octopuses, an inspiration for monsters throughout history, get a fresh look through a new book that dives deep into the creatures’ mysterious lives
Octopuses, those whip-smart but bizarre cephalopods, seem to embody everything creepy and mysterious about the sea–the thought of their soft squishy bodies lurking in the oceans’ dark reaches has inspired monsters ranging from the Kraken to the Caribbean Lusca. Their otherworldly forms, heightened by unfurling arms, find their way into more modern monsters and villains too–think Disney’s sea witch Ursula or Spider-Man’s Doc Oc. And don’t forget the octopus-themed horror movies!

1) Octopuses are waaay old. The oldest known octopus fossil belongs to an animal that lived some 296 million years ago, during the Carboniferous period.

2) Octopuses have three hearts. Two of the hearts work exclusively to move blood beyond the animal’s gills, while the third keeps circulation flowing for the organs.

3) The plural of octopus is octopuses. The word “octopus” comes from the Greek, októpus, meaning “eight foot.”
4) Octopus arms have a mind of their own. Two-thirds of an octopus’ neurons reside in its arms, not its head.
5) Octopus ink doesn’t just hide the animal. The ink also physically harms enemies. It contains a compound called tyrosinase, which, in humans, helps to control the production of the natural pigment melanin. But when sprayed in a predator’s eyes, tyrosinase causes a blinding irritation.
6) Octopuses have blue blood. To survive in the deep ocean, octopuses evolved a copper rather than iron-based blood called hemocyanin, which turns its blood blue. This copper base is more efficient at transporting oxygen than hemoglobin when water temperature is very low and not much oxygen is around.