Pacific Octopus Eye

Photograph by George Grall, National Geographic

What appear to be hills and valleys surround the eye of a giant Pacific octopus from the Pacific Northwest. Enteroctopus dofleini can reach lengths of almost 30 feet (9 meters) with arms averaging 16 feet (5 meters) in length. Also known as the North Pacific octopus, the octopus exhibits both short- and long-term memory, just as all octopuses do.