Everyone knows what an octopus is, but there are a lot of interesting facts about them that a lot of people don’t know.
One thing that everyone does know is that they have eight arms…except some people incorrectly call them tentacles. (Squid have eight arms and two tentacles.) Those arms are lined with suckers, and octopuses squirt an inklike substance to escape from predators.
Something that’s less well known is that they are by far the most intelligent invertebrate. (Well, only somewhat more than other cephalopods.) In fact they’re more intelligent than anything that’s not a mammal or a bird, and smarter than a lot of those as well. For example they solve mazes better than rodents, and are known to use tools.
Just like their brains, their eyes are also large and well-developed; and lack the blind spot that vertebrate eyes have.
And another thing is that they are far better than any lizard at doing what the chameleon has come to symbolize culturally; changing color, especially for camouflage purposes. The mimic octopus goes even farther, and contorts its body into various shapes to look like other animals, like a lionfish or a sea snake!
By the way, apparently “octopuses”, “octopi”, and the obscure “octopodes” are all considered correct enough to be in dictionaries, though “octopi” is based on the mistaken assumption that the “pus” part is of Latin origin rather than Greek.