Animals & Exhibits    >    Animal Guide    >    Octopuses & Kin    >   

Day octopus

Day octopus

On Exhibit: Tentacles

Animal Facts

  • Scientific Name

    Octopus cyanea

  • Animal Type

    Octopuses & Kin

  • Diet

    small crabs, other crustaceans, molluscs and fishes

  • Size

    to 31.5 inches (80 cm)

  • Relatives

    squid, cuttlefish and nautilus; Phylum: Mollusca; Class: Cephalopoda

At the Aquarium

How do our beautiful day octopuses get to the Aquarium? They take a plane, of course! A longtime colleague on Oahu carefully prepares the animals for a direct flight from Honolulu to San Francisco. Our aquarists drive up and meet the plane, ensuring a safe and speedy trip to Monterey.

The day octopus happens to be one of the most athletic and active species, says Curator of Husbandry Operations Paul Clarkson. "Pound for pound, it's about the strongest octopus we've ever exhibited. They like to huff and puff and blow water." Combine this strength with the animals' natural cleverness, and you have a real Houdini on your hands. "They're very willing to tear things up and escape," says Paul. "As a result, we've built a strong, five-foot cowling around the display."

The good news for visitors: because of this hyperactive personality, and the fact that this species is most active during the day, this is likely to be one of the most entertaining animals in the exhibit.

Natural History

The day octopus roams the reefs in tropical waters from Hawaii to East Africa. The large, almost three-foot-long predators are short-lived, surviving just one year and breeding only once.

While most octopuses hunt at night, this species spends its days stalking crabs, clams and fishes. Because it forages during daylight, it has exceptional camouflage skills, and can transform its skin into long, lumpy ridges, mimicking nearby corals, rocks or algae.

After foraging, an octopus usually retreats to its den to eat at leisure. It kills its prey (crabs are a favorite food) with venom secreted from its salivary glands, then cracks the shell with its sharp beak. It can also drill a hole in the snail's shell with its radula and inject a chemical that separates the snail's flesh from its shell. An octopus deposits empty shells outside its den in a pile–commonly called an "octopus's garden."



This species is fished commercially and recreationally throughout its range. As with other sea life, pollution, overfishing and habitat destruction pose serious threats to cephalopods.

Cool Facts

The octopus is a highly developed marine mollusc. It has three hearts—one pumps blood through the body and the other two pump blood through the gills. Researchers consider octopuses to be the most intelligent invertebrates—maybe as intelligent as a house cat.

Although it has excellent eyesight, an octopus uses touch and smell to find food—thousands of chemical receptors and millions of texture receptors line the rims of its suckers. It scours the sandy seafloor to flush out small prey, or crawls in and out of rocky areas to hunt crabs and shrimp.

The octopus begins life as larvae in the intertidal and shallow subtidal zones, spending a short time drifting as plankton in early stages of development.

 Animal Guide Home