Useless Factoid Thursday

Here at sEa_sick, we pride ourselves on collecting, assimilating, collating, and harboring useless, nonsensical, and completely irrelevant information for dissemination at a mere moment's notice. While reading my fellow blog-buddy, Fab, I noticed that he was prepetuating a terrible untruth about our fellow earth inhabitors, Carcharadon, or the wily shark.

Many folks mistakenly believe that all sharks have to swim all the time, and while I would love to believe that there is one ABSOLUTE and undeniable truth in this universe, this is not the one. While sharks do need to continually move water over their gills as a form of respiration and oxygenation, they can do this while lying absolutely still and flexing their spiracles (don't try this at home without adult supervision or without consulting your doctor first). Not all sharks have spiracles and so must swim around to let lovely ocean water ripple sensually through their mutliple gill slits, but the nurse shark is a prime example of a spiracle-bearer. She can rest unmoving in caves, grottoes, swim-up bars, and right out on the sandy floor until some divers come along to spoil her oceanic dreams.

However, upon closer inspection, what we find is that this myth arose not from an oxygen standpoint, but from a sleep perspective. We assumed that since sharks swam arround most of the time, that they didn't sleep and HAD to move around for this whole respiration thangy. When, in fact, it has everything to do with the absence of the ever-important and mostly ignored, swim bladder. Most fishes possess a little internal balloon that can be handily filled with air, or lighter than water substances (helium is not recommended and rather hard to come by in pelagic conditions) in order to give them buoyancy so that they don't go sinking off into the depths when they want to rest their little fishy fins. Sharks, alas!, were out eating reckless swimmers and other flotsam the day that Darwin was handing out swim bladders and so, if not in shallow waters with tolerable atmospheric pressures, must swim, swim, swim.

And there, my faithful blog-populace, is the undoing of yet another slanderous shark myth. (AND, did you know that boy sharks have two, yes 2!, peniseseseses... woohoo!)