Spree Killers of the Deep

A while back, I came across this piece in New Scientist about dolphin killing sprees.  (There’s actual video of the dolphins killing a harbor porpoise here, but be warned that some folks might find it slightly grim.  On the video, you can hear the (human) witnesses screaming.)

It reminded me of one of my all-time favorite documentaries, an episode of Nature called The Octopus Show.

I used to have this episode on videotape (yes, I’m old school, and yes, I’ve heard of TiVo, thanks), but I showed it to so many people that it eventually snapped and gummed up my VCR.  But, thanks to the miracle of the internet, I can share my favorite outtakes with you.

Which brings me back to, um, murder.

A few years back, the Seattle Aquarium put together a large exhibit containing, among many other things, specimens of spiny dogfish shark and giant pacific octopus.  They’d never tried this, and it was a little risky, because the spiny dogfish is known to eat the occasional octopus.  But they figured that their octopus would probably be okay, because octopodes are Masters Of Disguise.  (In addition to changing their coloration to match their surroundings in real time, some cephalopods can even change the texture of their skin to mimic rocks, coral, or whatever they’re hiding behind.  They’re incredibly good at hiding, as this video shows.  It’s a few minutes long, but very worthwhile, especiallly if you watch it through to the end.) 

So they put it all together… only to find their sharks turning up dead in the morning.  And it was a vexing problem.  If I remember the full episode correctly (though it’s been a few years, so I might not), I think they even performed a necropsy on one of the dead sharks, trying to figure out what happened.  No dice.  They completely cleaned the tank to remove any possibility of microbial or fungal problems.  No dice.  So finally one of the researchers stayed up all night with a camera.

And saw this.  (There’s slightly better video (but at the price of corny narration) here.)

It’s not clear to me if the giant pacific octopus actually ate the sharks after killing them, but I kind of doubt it, because if it had been eating them surely there would have been telltale signs of predation on the dead sharks that would have tipped off the researchers right away.

I’m probably mis-remembering the details to make them more sensational for myself.  But either way, I like to imagine that the octopus killed those sharks just because it could.

And that’s not the only time somebody has had to sleep on the laboratory floor just to figure out what the hell the octopodes have been getting up to in the middle of the night.  Not even close.  For instance, there’s Otto the Octopus, who resides at an aquarium Germany.  Apparently he got tired of having a light shone on him 24/7.  So what did he do?  Oh, he broke that sucker.  Broke it good.  With malice aforesight.  You know,

when he wasn’t busy trying to break out of his tank with a rock.

Another gem from The Octopus Show is video of an octopus slithering out of its own tank, pulling itself across a table, and then slithering into another tank containing tasty food.  I can’t find video of that one, but it sounds like it’s a common tale among people who work with cephalopods.  They’re freaky smart.

Which isn’t to say the bottlenose dolphin is a slouch, because it clearly isn’t.  But in a battle of wits, I’m putting my money on the octopus.

(What about those cold-blooded dolphins?  I think that they’re taking the rap for something else.  I think this is to blame.  But not to worry, because those billionaires in their robotic-dolphin-submarine-jetskis will eventually have their hands full battling robot sharks.   (That one’s for you, Sam.))

And finally, any discussion of sharks and cephalopods wouldn’t be complete without mentioning this.