Octopuses (or octopodes, if you're feeling particularly pedantic) have long caught people's imagination: they squeeze through tiny gaps, occassionally display bizarre behviour, and change the colour of their skin. The latter, which I've taken for granted since childhood, appears to be more complicated than previously thought:

But how does an octopus decide what animal to mimic, what colors to turn? Scientists have no idea, especially given that octopuses are likely colorblind.

But new evidence suggests a breathtaking possibility. Woods Hole Marine Biological Laboratory and University of Washington researchers found that the skin of the cuttlefish Sepia officinalis, a color-changing cousin of octopuses, contains gene sequences usually expressed only in the light-sensing retina of the eye. In other words, cephalopods—octopuses, cuttlefish, and squid—may be able to see with their skin.

As fascinating as I find this, perhaps you shrug and brush it off as an interesting but unremarkable physiological trait. Perhaps behaviour is more your thing —

Occasionally an octopus takes a dislike to someone. One of Athena’s predecessors at the aquarium, Truman, felt this way about a female volunteer. Using his funnel, the siphon near the side of the head used to jet through the sea, Truman would shoot a soaking stream of salt water at this young woman whenever he got a chance. Later, she quit her volunteer position for college. But when she returned to visit several months later, Truman, who hadn’t squirted anyone in the meanwhile, took one look at her and instantly soaked her again.

Either way, it appears octopuses are not to be underestimated.

Source: Orion Magazine.