Photo: Bill Abbott, Creative Commons
Deeper Waters
Octopus
On this Page
Two octopus species call the bottom of Kwilákm home: the Pacific red octopus (Octopus rubescens), which can grow to 61 cm arm tip to arm tip, and the Giant Pacific Octopus (Enteroctopus dofleini), which is, by far, the largest octopus species in the world, can weigh up to 50 kg, and span more than six metres.
First Nations stories often portray the octopus as a powerful sea-spirit helper to the chief of the undersea world. The octopus is sometimes depicted as a monster that can devour canoes and even whole villages. The octopus features in the art of healers, perhaps due to its ability to change colour and texture and regenerate lost parts—if an arm is damaged or lost in combat, the part is rapidly repaired or replaced.
Octopi are shy creatures, doing their best to evade predators. Octopi camouflage to avoid detection, changing both colour and skin texture to match their surroundings. If an octopus is certain it has been detected it may jet away, sometimes ejecting ink via its funnel directly at the pursuer.
Active and swift predators, octopi eat a wide variety of invertebrate and fish. In turn, they are eaten by larger fishes and mammals such as seals and humans. They leave the security of their den on hunting trips mostly at night when most visual predators are at a disadvantage.
Click on the photo below to see a video of a thumb-sized, juvenile Pacific red octopus on the prowl, filmed by Bowen diver Adam Taylor:
From a human point of view, octopi seem amazingly put together creatures. They have three hearts: a systemic heart that circulates blood around the body and two smaller hearts to pump blood through the gills where carbon dioxide is given off and oxygen is absorbed. Octopuses use one central brain to control their nervous systems and a small brain in each arm to control movement. They’re also known for having pale blue blood thanks to a copper rich protein called hemocyanin in their bloodstream which is used to transport oxygen.
On the underside, in the centre of the eight arms is the octopus’mouth, containing a horny, parrot-like beak and a radula. The radula is a file-like toothed structure in the mouth—tiny teeth that can drill holes or shred prey.
Other than its beak, the octopus has no hard parts at all, and this enables it to crawl through unbelievably small openings. Giant Pacific octopi (GPO) in Kwilákm learn that crab traps are a potential source of quick and easy food. The octopus crawls into the trap, kills and consumes the crabs, then squeezes its way out of the trap to return to its den where it digests dinner.
The GPO has two rows of 200 suckers per arm and eight arms or 1,600 suckers in total. The largest suckers can reach six cm in diameter and can support about 16 kg each. In theory, the grip of the approximately 1,600 suckers of an octopus spanning less than two metres could have total sucking capacity of almost 13 tons.
Bowen Island SCUBA diver Adam Taylor has spent many happy hours in the company of Kwilákm’s octopi. Learn about Adam’s Close Encounters of the Octopus Kind.
For more about octopus in the Salish Sea: Super Suckers, The Giant Pacific Octopus by James A. Cosgrove & Neil McDaniel, Harbour Publishing. Available to borrow from the Bowen Island Public Library.