I came across this news event back in April, and collected a few pieces of information to add to the story. So here is the start, the report that an octopus ( more specifically a Cyanea species) escaped from an aquarium. The staff called this guy “Inky” which obviously must have upset this animal, as he escaped when one night a 6 inch opening was left on top of the aquarium.
A well-loved octopus named Inky escaped recently from the National Aquarium in New Zealand. Aquarium manager Rob Yarrall says the lid to the octopus’ tank was left slightly ajar after maintenance one night.
You say that there’s no way a big octopus could pass through a gap 6 inches wide? Do you want to see what an octopus can do in tight spaces? So, here is a link (http://video.nationalgeographic.com/video/octopus_cyanea_locomotion) to a video from National Geographic that shows just how a large octopus can squeeze into, and move through a pipe a few inches in diameter. The makers of this video filmed the octopus in a plexiglass container, so the details show pretty nice. The weight of the octopus doesn’t matter much, because the octopus has no bones, and it’s muscles can push and pull the soft body through small diameter (like a quarter) openings.
Is it just me who thinks that we (members of the human race, in general) are being outsmarted? Is it too far fetched to think the octopi are allowing themselves to be caught just to collect information about us, and to test if we can build aquariums that represent a significant challenge for them?
Octopus vs squid and cuttlefish
This is a good time to mention that the squid is a very different animal from the octopus. While both are invertebrates, and both have remnant of their ancient shells, they also have differences relevant to the escape in the news. The squid (and the cuttlefish) has two very long, fleshy tentacles, in addition to the eight arms. The octopus has only eight arms. The squid also has a solid tissue in them, which is scientifically called the pen. You might be more familiar with the pen in it’s commercial form, the cuttlebone. Most of us buys the cuttlebone for our pet birds; the cuttlebone is good dietary source of calcium, magnesium, and other metals. Remember that the octopus doesn’t have bones? No surprise then that the cuttlebone makes it impossible for the squid to pull off the same tricks of squeezing through small openings.