Sharks: Part One, by Meghan

It is not a lie that sharks "fall asleep" (quotations necessary) when they are turned over on their backs. For several species of sharks, being inverted puts the shark into Tonic Immobility," an "unlearned behavioral response characterized by a state of immobility and torpor." "Tonic immobility can be induced by various procedures which place the subject in an 'unnatural' posture or situation, which has the effect of altering the usual course of its sensorimotor and emotional interchanges with its environment" (http://www.springerlink.com/content/hv211n88926r5563/fulltext.pdf?page=1). Studies were originally completed on Lemon sharks, but later studies proved a similar response in Tiger, Great White, and Smooth Dogfish sharks as well.

So, if you place a shark in an "unnatural posture or situation," its senses are flooded and it will drop into a catatonic state.

WHAAAAAAAAAT?

I know, it may sound like a lie (it did to my friends, thus inspiring the title for this blog) but I swear to you on all of my Harry Potter paraphernalia that I am telling the truth. Check it out here. This crazy awesome guy uses the tiny electromagnetic pulses created by the metal glove in the salt water to overload the senses of this shark and perform this incredible feat:



Marine biologists, such as the one you just saw, use tonic immobility as part of their research methods to place various tracking devices on the sharks. And humans are not the only ones to use this insane biological response to achieve their purposes; Orcas have also learned of the benefits of tonic immobility. Often in their hunting of Mako and Great White sharks, the Orcas will work to invert the shark, cutting off its ability to fight back, and allowing them to feed.


Did you just say "Whaaaaaaat" again? I thought you might. Yes, yes, tonic immobility seems impossible, but alas, nothing is impossible here on liesaboutsharks.