OK

Last week’s MLS poll gave the nod for Smooth Dogfish Sharks to be the topic for today’s diary, but I’ve been busy with other things and it will have to wait until next week. So today I present Stupid Octopus Tricks, starring Violet the Octopus.

I’ve had Violet for about a month. A friend of mine runs a fishing trawler and one of his crew noticed her clinging to the net as it was being brought on board. Fortunately he had stopped the winches and pulled her free just before she would have been crushed by several thousand pounds of fish.

Octopi are extremely intelligent creatures, as was highlighted in a very good blog post by Shirah. Not only are they able to learn, but they are capable of reasoning and problem solving, a talent lacking universally among invertebrates. They also are very good with face recognition when kept in captivity, quickly learning who feeds them. When I or one of my staff approach her tank she pokes her head out of her midden (that’s an octopus den) and a flash of purple appears around her eyes (hence her name). Once she’s sure it’s one of us she reaches an arm or two toward the glass and then comes out for a greeting. Or to beg for food, but I like to think it’s a greeting. If a stranger comes near her tank she will watch them closely but not leave her den.

Octopods in captivity are surprisingly tactile. Touch is one of their most important senses and once they get to know you they love to touch hands. Like a dog’s sense of smell, this is their main method used to experience their environment. Although they do have extremely good eyesight, they are very nearsighted. That may seem contradictory, but within about eight feet their eyesight is perfect. Past eight feet they can hardly see at all.

I’ll do a followup diary on these animals at some point to get into more of the biology of these incredible animals, but for today I’d like to show you a short movie we made of her ability to problem solve. Here’s the problem: How to get a crab out of a screw-top glass jar. We helped her a bit before shooting this by first placing a crab in a jar without a cover. Of course, she just reached right in and plucked the crab out. Octopi love crabs. Next we placed the cover on and just barely turned the lid. She discovered that if she turned the cover a bit it would pop off and she could get the food. Finally, we turned the cover on completely and let her go at it.

I apologize for the quality as this was taken with the video feature on a digital camera. Also, because they don’t like bright lights I keep her aquarium lights covered in red tubing to cut down on the glare.

Pretty cool, huh?

One last thing. Please don’t rush out and buy an octopus now. I’ll get into this a bit more later, but they are very, very difficult to keep alive in captivity. Water quality must be kept in perfect condition at all times. This means a top notch filtration system, protein skimmers and doing a partial change of the aquarium literally every day. They are also talented escape artists, as this video posted in Shirah’s diary demonstrates.

Other diaries in this series can be found here.

No poll today, as dogfish already won. See ya next week.

Originally posted to Mark H on Fri Feb 09, 2007 at 12:09 PM PST.

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