2007-10-19 08:05:14 · 7 answers · asked by sam 1 in Pets ➔ Fish
The simple explanation: http://amos.indiana.edu/library/scripts/fishdrink.html
A more scientific explanantion: http://www2.hawaii.edu/~delbeek/delb11.html
This not only goes for MOST fish, but any other organisms that live in salt or freshwater. Aquarists can make use of this since fish can regulate their salt/fluid balance better than invertebrates. If a freshwater fish gets a parasite, a traditional treatment is to add some salt to their water of immerse them in a stronger salinity salt bath. The parasite is affected more and will drop off and die from the higher salt content. Fish actually benefit from having a little salt in their water (the amount tolerated will depend on the species of fish), but even if they're put in sea-strength water, they can survive for a few minutes, although they'll be stressed. So salt is one of the easiest and cheapest parasite treatments because the parasites don't tolerate salt as well as the fish (although the fish needs to be put back into freshwater soon after being "dipped" in a salt bath. The opposite is true for saltwater fish and their parasites. You lower the salinity or give them a freshwater dip.
I had to specify "most" fish earlier because some brackish fish (those that live in estuaries where saltwater and freshwater mix) can often live in either if the salinity is changed over the course of a few days. Some common fish that can do this are guppies and mollies (I currently have a breeding colony of saltwater guppies in a 29 gallon marine tank).
That should answer both this and your reverse question that you posted.
More on the use of salt in aquaria: http://www.skepticalaquarist.com/docs/health/salt.shtml
http://www.practicalfishkeeping.co.uk/pfk/pages/show_article.php?article_id=335
2007-10-19 09:07:12 · answer #1 · answered by copperhead 7 · 1⤊ 0⤋
Because these fish have lived in a fresh water enviroment for centuries and salinity past a certain percentage will be toxic to them.
2007-10-19 09:09:26 · answer #2 · answered by Anonymous · 0⤊ 0⤋
For exactly the same reason why it is bad for you to drink salt water instead of fresh water. It disrupts your internal chemical balance and you will die.
2007-10-19 08:29:58 · answer #3 · answered by rowlfe 7 · 1⤊ 0⤋
Freshwater fish dont need the salt and it can kill them.
2007-10-19 08:10:53 · answer #4 · answered by Akasha 3 · 0⤊ 1⤋
yes! it will throw their internal balance completely out of whack, causing every individual cell in their body to explode, killing them.
2007-10-19 08:10:22 · answer #5 · answered by FishRfine 6 · 1⤊ 0⤋
They die. That, usually, is a bad thing.
2007-10-19 08:15:45 · answer #6 · answered by Vince M 7 · 0⤊ 0⤋
because it will kill them
2007-10-19 12:06:46 · answer #7 · answered by balla 3000 2 · 0⤊ 0⤋