Octopus

Photo: Giant Pacific Octopus

Although 9 species of octopi have been recorded from British Columbian waters, most are small or occupy offshore habitats. The giant pacific octopus, (Enteroctopus dofleini), is the only species in British Columbia large enough and common enough to currently attract directed fisheries interest.

Life Cycle

The Northern Giant Pacific Octopus (Enteroctopus dofleini) is a large cephalopod mollusc distributed along the rocky areas of the Pacific coast from the intertidal zone to depths of over 100 m.

These creatures are primarily nocturnal predators that feed on crabs, prawns and a variety of molluscs and small fish. Its beak, deeply set in the white flesh at the apex of its arms , is a black horny nipper arrangement that resembles a parrot's beak. It only uses this to help it crack crab, however, and is difficult to get it to use its beak in self-defense (Dan H. McLachan and Jak Ayres, 1979).

The octopus can change colour from a mottled white to a deep red and brown in one-tenth of a second. They also have an amazing ability to squeeze into tiny places and make their skin take on the texture of their surroundings. These factors give octopi a great amount of defense from its three greatest predators, wolfeels, lingcods, and scuba divers.

During the breeding process, a male donates with one arm a pencil shaped, transparent, gelatinous sack of sperm into one of the females large intake ports. Once bred the female searched for a proper lair in which to lay her eggs, usually settling in a cave twice her size and with an opening so small that she can barely make it through. Females brood their eggs on the ceiling of their dens. These eggs are the size and colour of white rice and there are approximately one or two quarts of these. To avoid contamination and the risk of predators the female will not leave the lair while guarding her eggs. She lives off the fats and proteins of her own body and will ultimately die having consumed herself during this brooding process.

The young are planktonic and remain in the water column until they are 50 mm in length, at which point they descend to the bottom. Octopi mature in about 2-3 years, at a size of 12 kg for males and 20 kg for females. They may grow to 9 m in length, measured from tip of tentacle to tip of tentacle.

Publications

Gillespie, G.E., G. Parker and J. Morrison. 1998. A review of octopus fisheries biology and British Columbia octopus fisheries. Can. Stock Assess. Sec. Res. Doc. 98/87. 66 p.