Why shark cannot stop moving?

Question

Why shark cannot stop moving?

Answer 1

sharks will not float, the do not have the abilty, they must keep moving in order to stay where they need to be, most sea creatures do not sleep

Answer 2

because it needs the water to pass through the gills or it'll die

Answer 3

Most species of sharks do not have to keep moving to breathe. They pump water through their gills. A small number of species, mostly ocean-going types, have lost the ability to pump water through their gills so have to keep swimming.

More info here - http://en.wikipedia.org/wiki/Shark#Respi...

Answer 4

There is a myth that sharks, unlike the bony fishes, cannot circulate enough water through their gills if they do not keep moving. But this is simply not true; there are quite a number of sharks that spend lots of time lying on the bottom in relatively shallow water.

Answer 5

cause they won't float

Answer 6

they would die. water going through there gills gives them oxygen

Answer 7

because its a fish

answer mine

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