|Octopus image shown here: by Noel Feans ((CC BY 2.0)|
While you won’t be able to hire the octopus to write your next term paper, they are remarkably intelligent animals with brains that are proportionately larger, by body weight, than those of the biggest dinosaurs. Perhaps that’s why they are still with us.
Brain size, by itself, means little. What really counts is the number of neurons in a brain. Humans have around 100 million neurons to brag about; octopi have around 130 million neurons in a brain that extends outside of their malleable heads into their arms.
Scientists have discovered that if you cut off an octopus arm, it retains enough intelligence to continue searching for tidbits of food. Unfortunately, arm-only intelligence has its limits. The disembodied octopus arm cannot remember that it doesn’t have a mouth or stomach anymore, so it does not have a bright future on its own.
Jennifer Mather (see her book: Octopus: The Ocean's Intelligent Invertebrate), a leading researcher into Octopi intelligence has documented other octopus feats of mental audacity including the ability to open jars and childproof caps on pill bottles. She has seen them playing “ball” by blowing air into a pill bottle and bouncing it off the side of aquarium and has documented octopi gathering and arranging rocks at the entrance to a den to lock out predators. They are also able to recognize specific humans. In aquariums, they will take a liking to some caretakers, gently grasping their hands with their tentacles, while squirting water into the faces of caretakers they don’t like.
So how did octopi evolve such highly developed intelligence? Mather speculates that it was an evolutionary adaptation to compensate for the gradual loss of their hard shell, leaving the delicate creatures with few defenses except the ability to outsmart their predators. The type of intelligence and consciousness required to be a smart octopus is not necessarily comparable to the intelligence of higher mammals. But they are, nevertheless, impressive even by human standards.
Here's some links if you want to learn more fun stuff about octopus? (or just watch some cool octopi videos) :
Amazing Octopus Videos
How Octopus Swim: Swimming With Octopuses: Octopi Locomotion