Posted on 03/06/2012 6:48:36 PM PST by DogByte6RER
It turns out sawfish actually wield their snouts like chainsaw-toting madmen
On second thought, that's not entirely accurate. Comparing a sawfish to a "madman" might give you the impression that these cousins of stingrays are unruly or careless when it comes to dispatching prey with their serrated snouts, when, in actuality, recent evidence suggests the exact opposite to be the case. Truth be told, sawfish are a lot more like chainsaw-toting surgeons.
This observation was made by University of Queensland Biologist Barbara Wueringer, who used chunks of mullet and tuna meat to observe the predatory behavior of juvenile Pristis microdon — one of the seven known species of sawfish. In tomorrow's issue of Current Biology, Wueringer and her colleagues write that the rapid, back-and-forth swiping motion of a hunting sawfish is strong and accurate enough to "split a fish in half, impale it on the rostral teeth, or sweep it [to the sea floor]," where the sawfish could use the blade of its saw to pin its prey in place.
The team's observations provide some of the most compelling evidence to date that sawfish use their snouts actively and deftly as a predatory weapon. But it's also significant for two other reasons.
The first is that it suggests sawfish are an exception to a long-standing rule. Sawfish, like other rays and sharks, can detect electrical fields given off by their prey. This adaptation allows these creatures to seek out food even in dark or murky environments. But according to Wueringer, fishes with elongated rostrums like the sawfish typically use them to either sense prey or manipulate it, but not both.
This video, however, shows that sawfish contradict this rule of mutual exclusivity. You won't find any actual prey in this clip; instead, Wueringer and her colleagues have positioned weak electrical dipoles at and above the ocean floor. Yet, according to the researchers, the swiping motions you see the sharks performing closely resemble those observed during feeding, and only occurred in the vicinity of the dipoles. Last year, Wueringer and her colleagues published the first findings to show that the saws of P. microdon are covered in thousands of electroreceptors — this video provides empirical evidence that these electroceptors are in fact used for active predation.
The second reason is that these findings could play a vital role in saving the sawfish — already classified as critically endangered — from extinction.
"Sawfish are skilled predators but, ironically, the saw is partly to blame for their global decline: the saw is easily entangled in fishing gear, perhaps as a result of targeting prey caught in the net," write the researchers. With any luck, conservationists operating with an improved understanding of how the sawfish hunts and forages will be better equipped for looking after and protecting these striking creatures.
The researchers' findings are published in the latest issue of Current Biology
http://io9.com/5890405/it-turns-out-sawfish-actually-wield-their-snouts-like-chainsaw+toting-madmen?tag=animal-behavior
That’s funny. I once chased my wife around the house with a battery powered Skil saw. Do I win a prize for being a madman?
Naked? If so then yes.
Yup! We were! But she had a power screwdriver. Years later, she was able to tag me at any time with a ball-peen hammer because I was dragging a walker around, waiting for a hip replacement to heal.
OMG, I can’t believe I just said all that. I am so screwed.
hahaha lol
How thick are the teeth on that saw? What are we talking here, 1/4 in. , 3/8ths.?
BFL
She must have gotten you pretty good with that power screwdriver in order to destroy your hip.
I can’t find a link to any video at that URL. Hope you can clarify...
Try linking to the original story from the IO9 link at the top of the thread. Scroll down a bit on the IO9 story and you should see a video window clip.
I posted this story from my pc, but I do have to say that I cannot bring up the video right now on the iPad.
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| GGG managers are SunkenCiv, StayAt HomeMother & Ernest_at_the_Beach | |
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Thanks DogByte6RER. Let's not forget the hammerhead shark, the screwdriver eel, and the measuring tape worm. And some others I haven't made up yet. |
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