2006-07-15 19:20:20 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Biology
The internal systems of freshwater and saltwater fish are different.
Freshwater fish living in an environment where the concentration of water outside their body is higher than inside their body are naturally hydrated due to omosis and do not have to drink water and frequently urinate.
Saltwater fish live in an environment where the concentration of waterh outside the body is lower thatn ther concentration inside the body. This is because the salt in the water lowers the concentration of water. Because of this, water naturally leaves the fish and goes into the water around it. Saltwater fish constantly drink water and hardly ever urinate to stay hydrated.
2006-07-15 19:28:46 · answer #1 · answered by I love to ball 3 · 1⤊ 0⤋
The quick and easy answer is that they would take in too much water and wouldn't be able to get rid of it.
More technically, marine fish are used to salt - water travels from areas of low salt to high salt, so their bodies are adapted to getting rid of as little water as possible. When they are placed in fresh water (low salt) water starts moving into their bodies. If they cannot get rid of it (kidney output, for example) they will eventually flood their blood stream, and their bodies will shut down due to their dilution of necessary blood components (sodium, potassium, red blood cells, plasma factors, etc.)
2006-07-16 02:39:39 · answer #2 · answered by michelsa0276 4 · 0⤊ 0⤋
The same reason that we get diarrhea when we eat too much salty food.
The cells try to equalize the salinity in the water they are in, in doing so they release minerals that they need to function properly in marine fish or in our digestive systems loose a bunch of water and risk dehydration.
2006-07-16 12:31:34 · answer #3 · answered by corvis_9 5 · 0⤊ 0⤋
Marine means saltwater.
Salt water fish are burned and killed in freshwater.
Freshwater fish get poisoned and die in saltwater.
2006-07-16 02:28:45 · answer #4 · answered by Dan S 7 · 0⤊ 0⤋
Such a question seems quite clear,
Marine fishes need salt my dear!
2006-07-16 02:28:10 · answer #5 · answered by a_phantoms_rose 7 · 0⤊ 0⤋
One small thing, their red blood cells actually burst, not the dilution of their blood stream. this is the same reason IVs contain salts, so our blood cells do not burst. and fish kidneys are not used to retain water, they freaking live in it.
2006-07-16 03:05:00 · answer #6 · answered by anthotcool 4 · 0⤊ 0⤋
I think it is because they are salt water fish
2006-07-16 02:23:48 · answer #7 · answered by reddogcudda 3 · 0⤊ 0⤋