New discoveries about giant Pacific octopus


Last week, I posted about the 2nd Biennial giant Pacific octopus symposium that was to be held at the Seattle Aquarium. The meeting went off without a hitch. It was the first meeting I have attended in which talks from scientists were so seamlessly weaved together with talks from conservationists and educators.

Giant Pacific octopus are part of a class of mollusks called cephalopods, and possess some extraordinary characteristics. They are highly intelligent and dexterous, and are able to open jars, mimic other octopus, and get through mazes in lab tests with ease. (Here is a great article in Slate Magazine about octopus smarts.) They also have tiny structures in the cells just below their skin that allow them to rapidly change color. When watching an octopus in the wild, you’ll also see them change the texture of their skin to look impressively similar to surrounding kelps and algae. Giant Pacific octopus are the largest known octopus species, growing up to 30 feet from tip to tip. They live for 3 to 4 years and mate only once near the end of their life.

The symposium at the Seattle Aquarium last weekend presented on several aspects of giant Pacific octopus biology and ecology. Shawn Larson, curator of conservation research at the Seattle Aquarium, presented her genetic findings from specimens in Puget Sound, the outer coast, and other locations regionally. Her work suggests that there is some degree of mixing between geographically separated individuals and that there is little evidence of a genetic bottleneck, or reduction in genetic diversity, which we would expect to see if the population size had declined rapidly in association with human activities. David Scheel, from Alaska Pacific University, also gave a a fascinating talk about his work over several decades. He presented compelling evidence that giant Pacific octopus are actually comprised of two (or more) separate species, which can be distinguished both genetically and by morphological differences. In addition, he explored some interest ecological relationships between octopus in Alaska and their prey, suggesting that the adornments on some crab species, which were traditionally thought to be adaptations that make them less visible to predators, may also be texturally cryptic, meaning their texture allows them to blend in with their surroundings when octopus are groping around under the bottom sides of rocks. We also heard from Jennifer Mather, who is developing an ethogram for giant Pacific octopus, Reid Brewer, who has done extensive research on giant Pacific octopus population density in the Aleutian Islands, and many others.

Finally, the meeting honored an important figure in octopus science and conservation, who recently passed away. Roland Anderson was a biologist at the Seattle Aquarium for many years and was the reason the Aquarium began hosting this meeting two years ago. In his memory, the symposium will hopefully continue for many years to come, highlighting further discoveries about giant Pacific octopus and connecting biologists, ecologists, conservationists, and educators from all around the Pacific Rim.