Drink like a fish!

Do fish drink? Where did the phrase come from? Is it because they look like they’re continually gulping that people think they’re drinking all the time?

The constant movements of their mouth is actually so that they can draw water past their gills in order to breathe.

So, do they drink? Well… fresh water fishes don’t really drink all that much. Their skin and gills are somewhat “leaky” and they actually draw water into their body passively. The excess water is excreted through their kidneys as dilute urine. The opposite is true for marine (salt water) fishes. Body fluids are lost through their “leaky” skin and gills and they counteract this by drinking a lot of water and producing little urine.
—
Now on: Twitter – Blog – Facebook – Linkedin – Flickr