The North Pacific Giant Octopus (Enteroctopus dofleini) is a large cephalopod belonging to the genus Enteroctopus. It can be found in the coastal Pacific Northwest, usually around the depth of 65 meters (about 213 ft.). It can, however, live in much shallower or much deeper waters. It is arguably the largest octopus species, based on a scientific record of a 71 kg (156.5 lb) individual weighed live.

Octopuses are thought to be one of the most intelligent invertebrates and can change the color and texture of their skin to blend in with rocks, algae, or coral to avoid predators. Some species of octopus have been reported to unscrew jar lids to retrieve food and mimic the behaviors of other octopuses and also other sea creatures such as sea snakes and lion fish. Giant Pacific Octopuses are capable of solving complex puzzles. This species of octopus commonly preys upon shrimp, crabs, scallops, abalones, clams, and fish. It procures food with its suckers, which is then crushed with its tough "beaks" of chitin.

The Giant Octopus is extremely calm and they held a regular spot on display at the Seattle aquarium over the years. Then the keepers decided to move one of the Giant Octopus in to a large tank filled with sharks and other big fish. They purposely picked a larger octopus fearing that it'll get killed by predators like shark. They assumed that the octopus strength and camouflage would keep it safe. As it turns out, they were tragically mistaken.

Since then, each week keepers were finding shark carcasses in the bottom of the tank. The 3-4 foot sharks kept vanishing at an alarming rate. Curious by the fact that the so called top of the food chain was defeated by an unknown predator, the keepers decided to stay up and film the culprit. To their surprise, the predator is none other than the Giant Octopus! They learned some thing about this species they never imagine. It was a big surprise to find out that sharks were taken by octopus, a mere invertebrate. Now school books might need to re-categorize top predators.

Source : marine.alaskapacific.edu
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