about salt and fresh water fish.?

Question

is it true that fresh water fish will lose water(weight) from the excess salt if they go into salt water because they are not used to drinking water and is it true salt water fish will gain water(weight) in fresh water from the excess salt because they are used to drinking water. if true why? (in words a pre teen will understand). if you don't understand the question say so and i'll rephrase it

Answer 1

I'm confused by the question but I can tell you that fresh water fish can tolerate SOME salt in their water and it has some therapeutic benefits to it, but fresh water fish DO NOT "drink" water, only salt water fish "drink" water.

There are certain times that you give fresh water (fw) fish a salt dip or salt bath. A salt bath is a good way of treating the fish without damaging the beneficial bacteria. It is a good antiseptic and fungicide.

There are certain times that you give salt water (sw) fish a regular water bath. The freshwater bath will cause any parasites attached onto the sw fish to let go and remain in the freshwater (to die a lonely death). Otherwise, parasites left to their own will reproduce very rapidly in captivity and usually infect all the fish in the tank.

Fish in fresh water tend to absorb water, because the saltiness of their body fluids draws in the water (by osmosis). Fish in saltwater tend to lose water from their bodies because the surrounding water is saltier than their body fluids.

The kidneys of freshwater species excrete excess water (the urine has low salt concentration) and those of marine species excrete excess salt (the urine has high salt concentration).

I don't know if this answers your questions or not, but I tried to cover as much as I could think of that might give you your answer.

Good luck!!! ;o)

Answer 2

OK....Environments will try to equalize themselves. For example if you have a container with water with a high salt content and put it in a bigger container with water with not salt content, if there is a way the water to move between containers the salty water will move out of the high salt container and the unsalted water will move in until they both have the same salt level.

It is the same with saltwater and freshwater fish. If you put a freshwater fish in salt water there body will loose water and gain salt, if you put a saltwater fish in fresh water it will absorb water and loose salt. It has nothing to do with drinking .

Only a few fish can survive this. Those are the fish that normally live in areas where salt and freshwater meet like were rivers empty into the ocean. A commonly kept fish that is like this is a mollie.

If this isn't clear let me know.

Answer 3

Hi, I think that the ones in the salt water would die maybe because the salt would not allow them to breathe properly and they would die. On the other hand the ones in the fresh water (I think) would be okay since the things that they breathe with wouldn't be blocked.

Answer 4

relies upon on what style of fish. Salmon stay contained in the sea yet spawn in freshwater. Their hatchlings start up existence in sparkling water then swim back to the sea. i'm no longer particular what organ helps them to attempt this (maximum likely the kidneys) yet a number of species of saltwater fish can attempt this. i have not heard of a freshwater fish that spawns in saltwater yet there are also fish that stay in estuaries the position salt and sparkling water blend. in case you've been to take a freshy and throw him in salt or vice versa they could likely die from kidney failure interior 10 minutes.

Answer 5

Have you studied diffusion in your science classes yet? This relates to the answer to your question, so I'll try to explain this as I go along if you haven't used this term yet.

What happens has to do with the membranes around each cell in the fish's body. Some things like water can pass through easily. Other molecules can be too big, or have an electrical charge (ions) and not be able to pass through without help, or at all. Salt is one from the last group - in water, salt (NaCl) separates into ions of Na+ and Cl-. These can only get in and out of cells with "help" and through specific passages.

Diffusion is the tendency for molecules to even out their spacing. This is why if you put a drop of food coloring in a glass of water and wait, soon all the water will be colored. Molecules of the color pigment will spread out from the concentrated area to the less concentrated areas. The same thing happens with smells - someone may be making coffee or baking in the kitchen, but you notice the smell in other parts of the house. This is true of salt and water inside the body of the fish as well. Each cell has to come into contact with a blood vessel so it can get oxygen and nutrients and get rid of wastes.

Now imagine that the concentration of salt inside the cell and out are different. The tendency of nature is that the concentrations should be equal. Since the salt can't move in or out on its own, what has to move is the water. So if a freshwater fish finds itself in a high concentration of salt (which will be absorbed into the bloodstream, making the salt concentration greater outside the cells), water will need to move out of the cells to dilute the salt. A saltwater fish in freshwater will have a greater concentration inside its cells so water will have to be pulled in.

The effect on the fish will depend on the exact concentrations of the salt. All organisms need to have some salt for their cells to function, so what's inside the cells never equals zero. Because freshwater environments may have even lower concentrations of salt, fish found in freshwater have special cells in their gills to absorb any salt available to give them the salt they need. A little bit of salt in their water benefits them, so they don't have to expend as much energy to get it. But if they're in an environment where there's too much salt, too much water can be pulled out of their cells, causing them to dehydrate. This is also why people who are shipwrecked shouldn't drink seawater - you can drink constantly, but die of dehydration.

Saltwater fish have the opposite problem - there's too much salt in their environment, so they have specialized cells in their gills to remove the salt before it enters their bodies. But if they get too much freshwater, it can be drawn into their cells to the point where they "bloat".

Fortunately, fish are better at controlling the amount of salt and fluid in their bodies than are their parasites. This is why it's recommended to add a little aquarium salt for freshwater fish to treat disease and parasites, but to lower the amount of salt for saltwater fish.

Here's a link to another version of the explanation: http://amos.indiana.edu/library/scripts/fishdrink.html

I think this should answer your question, but if you need anything explained, fell free to email me through my profile.

Answer 6

the only change that would happen is they'd all die, they would go into shock and die