Eight-Armed Wonders

In the midst of crab season, there is another animal that tends to get some unexpected attention from local fishermen: the giant Pacific octopus. Not unlike many of us, a favorite food of the giant Pacific octopus is the Dungeness crab.

The giant Pacific octopus is an amazing creature that can even walk on land. Learn more at the Aquarium of the Bay’s Ocotpalooza from February 14-23.

By Mallory Johnson

Published: February, 2014
In the midst of crab season, there is another animal that tends to get some unexpected attention from local fishermen: the giant Pacific octopus. Not unlike many of us, a favorite food of the giant Pacific octopus is the Dungeness crab. This mischievous creature also likes to hide out in small den-like enclosures, and with no skeleton to get in its way, an octopus is able to squeeze its body into impressively tight spaces. So when an octopus happens across a crabber’s trap in the Bay, it’s like stumbling upon the jackpot. This explains why crabbers will often times pull up their traps only to find an octopus inside that has eaten all of their catch. Rather then throw the octopus back in the Bay where it will continue to eat their catch, often the crabbers will respond by killing the octopus or selling it to a restaurant to be served up as an appetizer.
In 2005, Aquarium of the Bay started a program to help these octopuses that unintentionally find themselves in the wrong place, by asking local fishermen to consider giving the Aquarium a call. The Aquarium will then take the octopus off the hands of the fisher, offering the octopus a safe new home with plenty of delicious crab. Since the program’s inception, Aquarium of the Bay has successfully rescued over 30 octopuses from an otherwise hasty demise. 
In honor of this eight-armed wonder, here are a few amazing facts about the giant Pacific octopus:
They have skin even Jennifer Aniston would be jealous of
Giant Pacific octopuses have amazing camouflage skills thanks to a little something called chromatophores. Chromatophores are pigment-filled cells with special muscles that allow the cell to quickly expand and contract. This movement of the muscle lets an octopus change the color of its skin within a fraction of a second. Giant Pacific octopuses can change from pale grey to dark brown and dark red, or can even display an impressive combination of colors at once. If that alone wasn’t impressive enough for you, these cunning creatures can manipulate their muscles to change the texture of their skin as well. They use small muscles to pull their skin up into little peaks called papillae, changing their skin from smooth to bumped, spiny or even horned, allowing them to blend in seamlessly with almost any environment. 
They can walk on land
Yep, you read that right, an octopus can walk on land, further solidifying my previous statement that octopuses are amazing. While it’s not commonly observed, octopuses have been known to climb out of the water and pull themselves across rocks to reach tidal pools. How does an aquatic cephalopod manage this? Their gills are located within a mantle cavity which is capable of holding water. Before they crawl onto land, they fill their mantle cavities with water, enabling the gills to continue extracting oxygen until the water is depleted of oxygen. After that point, the octopus is effectively holding its breath. While on land, the octopus can use its muscular arms and suckers to pull itself across the terrain.
Squid Ink is great for misdirection
Octopus ink is made primarily of melanin, one of the blackest, most opaque substances animals can produce. When threatened, an octopus can release this ink, providing it with a number of benefits for a quick getaway from its prey. There are two options for the octopus when releasing ink. One is to simply ink and create a smokescreen, which will effectively hide the octopus from the predators view while it swims away and finds a good place to camouflage itself. The second option is to mix mucus into the ink, producing a blob that bares a similar shape to the octopus. Also known as a psuedomorph, this blob offers an extra diversion for a quick escape. But the benefits of squid ink don’t stop there. Cephalopod ink contains an extremely irritating substance called tyrosinase. In addition to clouding the view of the predator, this substance temporarily blocks the predator’s sense of smell, irritates its eyes, and can clog its mouth and gills with mucus, making for a clean getaway for the cunning octopus. 
You can learn more about this eight-armed wonder by visiting Aquarium of the Bay for Octopalooza. From February 14 to 23, Aquarium of the Bay will be celebrating all things cephalopod with special presentations, market squid dissections and more. Find out more at www.aquariumofthebay.org
Mallory Johnson is the Public Relations Coordinator for Aquarium of the Bay, a nonprofit organization dedicated to protecting, restoring and inspiring the conservation of San Francisco Bay and its watershed.