Giant Pacific Octopus Enteroctopus dofleini Cephalopods: The octopuses and their relatives There are about 650 species in the class Cephalopoda, which includes the nautilus, squid, octopus, and cuttlefish. A cephalopod (CEFF-uh-luh-pod) has a complex nervous system, eggs that hatch directly into small versions of adults (instead of into larvae), and tentacles or arms around its mouth. The word “cephalopod” is made up of Greek roots that mean “head foot,” which describes the way a cephalopod’s arms and tentacles are attached directly to its head. Giant Pacific octopus fast facts Range: North Pacific Ocean, in nearshore waters up Eight arms and three hearts to 2,500 feet deep make one octopus Size: The giant Pacific octopus is the largest octopus All 100 or so species species. Typical weights for a full-grown giant Pacific of octopus have eight octopus range from 70 to 110 pounds. Most are less arms, each with two than 16 feet across from arm tip to arm tip. rows of suckers; no shell, Diet: Shellfish such as crabs, clams, abalone, and either inside or out; shrimp; fish and three hearts: one Life span: From three to five years for circulating blood Suckers: A total of 2,240 suckers on a female; males throughout the body and have about 100 fewer suckers two to pass blood over the gills to oxygenate Plural: Octopuses. If the roots of the word “octopus” it. An octopus’s bag- were Latin, the plural would be “octopi,” but since shaped body, or mantle, the roots are Greek, we say “octopuses.” contains organs such as Scientific classification: Kingdom Animalia; phylum kidneys, a liver, gills, a Mollusca (includes clams, snails, and octopuses); stomach, an intestine, a An octopus has two eyes that class Cephalopoda (octopuses, squids, cuttlefish, and brain, and reproductive are structurally similar to nautiluses); order Octopoda (the octopuses); family organs. On top of its human eyes. Octopodidae; genus Enteroctopus; species dofleini head, an octopus has two eyes that are structurally similar to human eyes; it has relatively good eyesight. An octopus’s intelligence is reportedly about that of a house cat. The octopus’s mouth is on its underside, where the eight arms meet. Its beak, made of keratin (KER-uh- Octopuses are reclusive tin) (the same material as our fingernails and hair), predators is the only hard part in the animal’s body, which Giant Pacific octopuses spend their days in small explains why octopuses are such escape artists. Any caves or cracks, where they are safe from predators. small space an octopus can fit its beak through, it can At dawn and at dusk, an octopus swims out to hunt fit its entire body through. for shellfish, bringing its prey back to its den to eat in peace. And the suddenly expelling water from its body through its octopus can be an siphon. Or it might squirt “ink” from its siphon, ambush predator—if an creating a false octopus shape that confuses the animal should pass by its predator while the real octopus jets away. den, that’s even better Like many other cephalopods, an octopus can than having to go out change colors in the blink of an eye. An octopus has hunting. It’s not above color patterns for camouflage, attack, escape, sex, a bit of scavenging, food, and curiosity. When a giant Pacific octopus is either, if it comes across resting, it is almost white; when it is aroused, it turns an animal that’s already bright red. When it is somewhere in between, it can dead. show a striking mottled pattern. To eat live prey, an Any small space an octopus octopus first bites it can fit its beak through, it can Making more octopuses with its beak and injects fit its entire body through. Octopuses come in two sexes. On the third arm on venom to paralyze the the right side of the male, the final four inches are animal. An enzyme that modified into an organ called a hectocotylus (HEC- the octopus then injects tuh-KAW-t’l-us), a structure without suckers that is begins to break down used to insert sperm ropes into the female’s mantle the animal’s protein, cavity. softening its muscles and The female attaches her fertilized eggs—tens internal organs over the of thousands of them—to the roof of her den and course of two or three stays with them for five or six months until they hours. Then the octopus hatch. Without ever eating, she guards the eggs from slurps the nearly liquid predators and blows water over them to keep them food out with its rasping clean and make sure they get oxygen. Once the eggs tongue, called a radula hatch, the female dies. After mating, the male also (RAD-yoo-lah). When stops eating and eventually dies. it’s finished, the octopus When they hatch, young octopuses are about a pushes the remains out third of an inch long and resemble adults, complete A giant Pacific octopus has the opening of its den, with suckers on their arms, ink sacs, and other about 2,000 suckers, used for creating an “octopus distinctive octopus features. Nearly all of these tiny feeling, tasting, and pulling. If garden” of empty shells. animals are eaten by fish and other sea creatures. all used together, they could pull Giant Pacific more than 700 pounds. With luck, though, one or two will survive to grow up octopuses are preyed and reproduce, continuing the long line of versatile, upon by seals and sea graceful, intelligent octopuses. lions, sea otters, some fish, and larger octopuses. An octopus might try to use jet propulsion to escape, This publication was funded by the National Sea Grant Text by Eileen Flory, museum/education assistant, Hatfield College Program of the U.S. Department of Commerce’s Marine Science Center National Oceanic and Atmospheric Administration, under Sources: Heimowitz, Paul, et al. “Giant Pacific Octopus: NOAA grant number NA060AR4170010 (project number A guide for responding to commonly asked questions”; A/ESG-4) and by appropriations made by the Oregon and Wood, James B., The Cephalopod Page, http://www. State legislature. The views expressed herein do not neces- thecephalopodpage.org/ sarily reflect the views of any of those organizations. Photos by Donna McCoy and Mark Peter © 2007 by Oregon State University. This publication may be photocopied or reprinted in its entirety for noncommercial purposes. Oregon Oregon Sea Grant’s Web site: http://seagrant.oregonstate.edu ORESU-G-07-002 Phone: 541-737-2716 or 1-800-375-9360.