Enteroctopus dofleini

By Tara Eisenberg
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Octopoda
Suborder: Incirrina
Family: Octopodidae
Subfamily: Octopodinae
Genus: Enteroctopus
Species: Enteroctopus dofleini

Geographic Range
North Pacific Ocean: this includes the ocean area off the northern coast of California, extending northward through Alaska to Japan.

Biogeographic Regions:
pacific ocean (native ).

Habitat
Octopus dofleini are bottom-dwelling, shallow water species occupying the Northern Pacific region. They live from low-tide levels to about 200 meters in depth.

Aquatic Biomes:
benthic ; coastal .

Physical Description
Mass
18 to 25 kg
(39.6 to 55 lbs)

Octopus dofleini are the largest of all octopods, with a 9.6 meter arm span. Like all Octopus, they have 8 long arms, which bear suckers.

Reproduction
Octopus dofleini mate when the male introduces his out-stretched hectocotylus into the female's mantle cavity, into which he ejects spermatophores. The hectocotylus is a male arm specialized for spermatophore transfer to the female. The spermatophore are deposited at the opening of the oviduct, and the spermatozoa are then stored in the female's oviducal glands. A female can lay 18,000 to 100,000 eggs. Eggs are placed in nests on rocks or sandy bottoms at depths less than 50 meters. Reproduction takes place during the autumn, in-shore at a depth of up to about 100 meters. Octopus dofleini usually mate only once. After mating, the males move into deep water and die. The females die after hatching their eggs.

Behavior
Medium to large sized Octopus dofleini are known to go through migrations. They move in-shore during the months of October and November and return to deep water between February to March. The cycle repeats when octopuses move to shallow water in late April to May, returning to deep water in August and September.

Food Habits
The young, planktonic hatchlings, are "neustonic feeders" (feeding on dead food). They capture krill by seizing it with their arms. By 43 days, young Octopus dofleini dart towards their food like squids. Adults feed on crustaceans, mollusks, flatfishes, redfish and sculpins.

Economic Importance for Humans: Positive

Octopus dofleini are a major commercial species in the world. They are the most common species caught by fisheries in northern Japan. About 20,000 metric tons are taken per year. There are fisheries for this species off Alaska and Washington as well. Alaskans catch them using the "pot" method, which is similar to the Japanese clay pots. The pots are placed on the ocean bottom and are pulled up when an octopus enters. Octopus dofleini are used for bait in long line fisheries and for human consumption.

Conservation Status
Even though the Octopus dolfleini are sought by many fisheries, they are not facing any threat to their existence. They reproduce relatively late in life, which might impede their recovery should they become endangered, but their mortality rate before spawning is only 1%.