Beautiful, bashful and brainy, the giant Pacific octopus leads a life of mystery. With a personality that's as complex as its appearance, this animal is a master of disguise that can solve a maze, recognize our aquarists, and has the power to jet across the exhibit in a whoosh of water.
A Mollusk Without Its Shell
Octopuses are mollusks—boneless invertebrates related to clams and snails. But they are no shell-bound mussel that lives in the mud. They're agile, smart and sneaky, armed with eight sinuous tentacles that are studded with suction cups.
Like other octopuses, the giant Pacific octopus is a master of disguise due to a complex system of pigment cells, muscle fibers and nerves. Millions of elastic cells under the skin contain colored pigments. By stretching these open or squeezing them shut from moment to moment, the octopus adjusts its skin color.
Eight-Armed and Awesome
Adults are stealthy hunters that eat a wide assortment of seafood, most commonly crabs, clams and other mussels. They catch their prey by surprise, using camouflage, jet propulsion and the sure grip that comes with having eight arms.
The Early Days
The largest octopus in the world hatches from an egg the size of a rice grain. The tiny hatchlings are just over a quarter-inch long and weigh 22 milligrams (less than a thousandth of an ounce). On day one, their eight little arms already have about 14 tiny suckers each.
In this Exhibit
An octopus is a little like a normal mollusk turned inside-out. It has a soft body, and its shell has been reduced to two small plates where its head muscles anchor, plus a powerful, parrot-like beak. Lacking a shell, octopuses protect themselves with one of the most sophisticated camouflage systems in the animal world.
An urchin "walks" on tiny tube feet, much like a sea star does. When an urchin finds a scrap of kelp—its favorite food—it uses its five rasping teeth to scrape away at the kelp and push tiny pieces into its mouth. This urchin feeds on plant and animal scraps that drift down from shallower waters. The fragile pink urchin is an abundant sea urchin off our coast. It may go for long periods without food, surviving on stores of fat.