Originally Posted by kfryman
Oh so they can just adapt easier than other fish, got it. Wonder why that is, like why only some fish but not others? I think I need a biologist lol.
I can't say for sure, but what makes sense to me is that they probably have very efficient ion pumps in their gills to control the ion concentration in their bloodstream, along with kidneys that can effectively dilute or concentrate urine to either conserve or rid the body of excess ions/water.
Just as a side note, anadromous fish such as salmon are pretty cool in that the ion pumps in their gills are reversible, allowing them to spend time in fresh and salt water. They can take in ions in freshwater with low ion concentrations and expel ions when in highly concentrated saltwater. The kidneys work in sync with this process. Kinda neat