Blood wastes are filtered by the kidneys. Saltwater fish lose water because of osmosis. Their kidneys return water to the body. The reverse happens in freshwater fish: they to gain water osmotically. Their kidneys produce dilute urine for excretion.
The density and pressure of saltwater is different from freshwater as is much of the bacterias and parasites. The acidity of the water is also of concern as the lower the PH the higher the acidity of the water. Saltwater being of a higher PH would not handle the lower PH of freshwater very well. Also if moving a freshwater fish to saltwater that fish will lose a great amount of water in it's body causing death and if the saltwater fish is moved to freshwater it will gain great amounts of water causing death.
Yes, as a fish moves ,from saltwater to freshwater, the concentrations of salt ions drops as freshwater enters the body via osmotic pressure.
Depending on if the fish lives in fresh or salty water they may urinate a lot (if they live in freshwater) or living in a salty environment can make them pee less but it's very concentrated.
Freshwater fish typically lose chloride ions through diffusion because their bodies are constantly trying to regulate osmotic balance with their surroundings. This loss is usually compensated for by actively taking in chloride ions from the surrounding water through specialized cells in the gills.
if anything it would be reasonable to expect it to lose mass.
Oceans can both gain and lose water. They gain water from sources like rainfall, rivers, and melting ice caps. They lose water through processes like evaporation and when water is locked into glacial ice. Overall, the balance between these inputs and outputs determines whether the oceans are gaining or losing water.
rainfall and evaporation
salt water fish drink alot of water compared to freshwater fish, their bodies and systems have been designed by god to cope with the salt. they are able to purge themselves of the salt in their diet. how they do it is a mystery to all but god.
water wheight is the wheight you gain/ lose in fuids for example when you dfo a activity that makes you sweat alot you lose water wheight but you will gain that wheight back as soon as you drink something
When freshwater fish lose their tail and the stub is all white, it could be a sign of fin rot, a common condition caused by bacteria or fungus infecting the fish's fins. It is important to treat fin rot promptly to prevent further infection and promote healing. Regular water changes, maintaining good water quality, and proper diet can help prevent fin rot in freshwater fish.
Because like many different specis of fish it depends on the specimen and were it was born, say it was born in a fish bowl, full of ordinary water, then it wouldn't leave it's actual habitat, but if it was born in salt water then it would have to live it's life in salt water.