All living beings including fishes need water for their
survival. One feels thirsty when once body is in urgent need of water. A fish
may get this feeling too, depending on its living conditions. A fish that lives
in fresh water may not get thirsty, but fishes that live in marine environment
get thirsty. Marine fishes loose large amount of water through the process of
osmosis. This is because the concentration of salt is higher in sea water than
in body fluid of fishes.
Due to this loss of water marine fishes drink water. Otherwise
it will get dehydrated and may die. The excess of salt that fishes absorb is
excreted by gills.
But in the case of fresh water fishes, the salt
concentration in body fluid of fish is much more than in the surroundings. Hence
water keeps coming into fish’s body through osmosis and excess water is excreted by gills again. So they don’t drink water.
No comments :
Post a Comment