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m in class eleventh so need it accordingly to my standard....

2007-03-15 05:53:01 · 10 answers · asked by richal 1 in Science & Mathematics Zoology

10 answers

Maybe? The African lake sharks mentioned above are bull sharks, they are able to live for long periods of times (years) in freshwater. Renown for going into rivers like the Amazon, the Mississippi and many others. Now they can live there but there's no evidence they can breed there, so yes they can live in freshwater but since they can't reproduce there they aren't a freshwater species.
Onto another case, a number of new species are being discovered in freshwater rivers, there's so little known about them that it's hard to tell if they are like the bull shark or if they are truly a freshwater species.
Check out this link for more info http://www.aquaticcommunity.com/sharkfish/freshwatersharks.php

2007-03-15 07:17:09 · answer #1 · answered by crazy.carabid 4 · 1 0

There were a couple of species living in the freshwater lakes of Nicaragua, up until very recently; they've been decimated through pollution and overfishing. Some individuals may still survive. Google for
Nicaragua freshwater shark
and
Managua freshwater shark

2007-03-15 06:28:55 · answer #2 · answered by Anonymous · 0 0

Widely.....no.

I think there are a few species of sharks that can travel into brakish waters for a short time, but at large...sharks are mostly Salt-Water animals.

2007-03-15 05:59:33 · answer #3 · answered by Observer 2 · 0 0

no sharks do not live in freshwater. though bull sharks come very cole to shore, thats in sea water

2007-03-15 06:00:00 · answer #4 · answered by Diptodip D 1 · 0 1

Another terrific question!

In order to carry out the complex chemical reactions that sustain life, all living things -- including sharks and people -- have a supply of water and salts in their bodies. Although skin and other living tissue looks solid, it actually has tiny pores in it. Small molecules such as water and salts can pass readily back and forth through the skin. But if there is more of one kind of molecule on one side of the skin than on the other, some of the molecules will move from an area of higher concentration to an area of lower concentration, through a natural process called 'diffusion'. Diffusion will occur until the concentration of that molecule is equal on either side of the skin. Diffusion is the same process that allows a sugar cube to completely dissolve in a cup of tea or coffee: the sugar molecules spread out from an area of high concentration (the cube) to an area of low concentration (the tea or coffee); eventually, all parts of the tea or coffee are equally sugary.

The sea is composed mostly water, but dissolved in the water are also various salts. The concentration of salts in seawater is usually about 3 to 4%. The living tissue of human beings and most fishes are considerably less salty than this. As a result, there is more fresh water inside the human or fish than outside in the sea. In response, water naturally diffuses from the body across the skin, as though attempting to dilute the outside sea. (The diffusion of water across a semi-permeable membrane is a special case of diffusion, usually termed 'osmosis'; in the interests of simplicity, I'll continue to use diffusion here.) Human skin is relatively water-tight, but fish skin in rather leaky. As a result, the bodies of most marine fishes are constantly losing fresh water to the surrounding sea. But all living things need a supply of water inside their bodies in order to function properly. What most fishes must do to restore the water their bodies need is drink lots and lots of seawater You've heard the expression, "Drinks like a fish"? Well, it's true: marine fishes drink seawater almost constantly. In order to get rid of the excess salt contained in the seawater, many fishes have specialized salt-secreting structures in their gills called "chloride cells".

But sharks have hit upon a different strategy. Instead of being less salty than the sea, sharks store certain metabolic wastes (namely, urea and trimethylamine oxide, or TMAO for short) so that their overall 'saltiness' is actually slightly greater than that of the sea. As a result, sharks do not continually lose their bodily supply of freshwater to the sea. Instead, any fresh water they need diffuses gently into their bodies through the mouth, gills, and other exposed membranes. Any excess water in a shark's body is filtered by the kidneys and excreted out an opening called the 'cloaca', located between the pelvic fins (the rearmost paired fins, behind the shark's belly). It's a very elegant solution to a significant environmental challenge. But it has its limitations.

If a typical sharks were to swim its very 'salty' body into fresh water, so much fresh water would diffuse into its tissues that the kidneys would have to work overtime in order to get rid of it all. This is a very energy-demanding process, and explains why most sharks do not enter fresh water: it's simply too much effort to keep excreting all that freshwater. But some sharks, such as the Bull Shark (Carcharhinus leucas), are able to enter fresh water for prolonged periods. They achieve this neat trick by greatly reducing their bodily concentrations of urea and TMAO. Even so, a Bull Shark in fresh water is slightly saltier than its surrounding environment, so that it must continually excrete excess water in the form of dilute urine. In total, some 43 species of sharks and rays (which are essentially flattened sharks) spend at least part of their lives in fresh water. But one family of South American stingrays -- the so-called River Stingrays (Potamotrygonidae) -- evolved from a marine ancestor to become thoroughly adapted to living in fresh water. So much so, in fact, that their bodies have lost the ability to manufacture urea and -- if placed in full-strength seawater, they quickly die. These freshwater stingrays are thus trapped by their biochemistry.

Sometimes, you can't go home again.

2007-03-15 06:12:14 · answer #5 · answered by man_vir_in 3 · 0 2

no...they live in salt water because
In order to carry out the complex chemical reactions that sustain life, all living things -- including sharks and people -- have a supply of water and salts in their bodies. Although skin and other living tissue looks solid, it actually has tiny pores in it. Small molecules such as water and salts can pass readily back and forth through the skin. But if there is more of one kind of molecule on one side of the skin than on the other, some of the molecules will move from an area of higher concentration to an area of lower concentration, through a natural process called 'diffusion'. Diffusion will occur until the concentration of that molecule is equal on either side of the skin. Diffusion is the same process that allows a sugar cube to completely dissolve in a cup of tea or coffee: the sugar molecules spread out from an area of high concentration (the cube) to an area of low concentration (the tea or coffee); eventually, all parts of the tea or coffee are equally sugary.

The sea is composed mostly water, but dissolved in the water are also various salts. The concentration of salts in seawater is usually about 3 to 4%. The living tissue of human beings and most fishes are considerably less salty than this. As a result, there is more fresh water inside the human or fish than outside in the sea. In response, water naturally diffuses from the body across the skin, as though attempting to dilute the outside sea. (The diffusion of water across a semi-permeable membrane is a special case of diffusion, usually termed 'osmosis'; in the interests of simplicity, I'll continue to use diffusion here.) Human skin is relatively water-tight, but fish skin in rather leaky. As a result, the bodies of most marine fishes are constantly losing fresh water to the surrounding sea. But all living things need a supply of water inside their bodies in order to function properly. What most fishes must do to restore the water their bodies need is drink lots and lots of seawater You've heard the expression, "Drinks like a fish"? Well, it's true: marine fishes drink seawater almost constantly. In order to get rid of the excess salt contained in the seawater, many fishes have specialized salt-secreting structures in their gills called "chloride cells".

But sharks have hit upon a different strategy. Instead of being less salty than the sea, sharks store certain metabolic wastes (namely, urea and trimethylamine oxide, or TMAO for short) so that their overall 'saltiness' is actually slightly greater than that of the sea. As a result, sharks do not continually lose their bodily supply of freshwater to the sea. Instead, any fresh water they need diffuses gently into their bodies through the mouth, gills, and other exposed membranes. Any excess water in a shark's body is filtered by the kidneys and excreted out an opening called the 'cloaca', located between the pelvic fins (the rearmost paired fins, behind the shark's belly). It's a very elegant solution to a significant environmental challenge. But it has its limitations.

If a typical sharks were to swim its very 'salty' body into fresh water, so much fresh water would diffuse into its tissues that the kidneys would have to work overtime in order to get rid of it all. This is a very energy-demanding process, and explains why most sharks do not enter fresh water: it's simply too much effort to keep excreting all that freshwater. But some sharks, such as the Bull Shark (Carcharhinus leucas), are able to enter fresh water for prolonged periods. They achieve this neat trick by greatly reducing their bodily concentrations of urea and TMAO. Even so, a Bull Shark in fresh water is slightly saltier than its surrounding environment, so that it must continually excrete excess water in the form of dilute urine. In total, some 43 species of sharks and rays (which are essentially flattened sharks) spend at least part of their lives in fresh water. But one family of South American stingrays -- the so-called River Stingrays (Potamotrygonidae) -- evolved from a marine ancestor to become thoroughly adapted to living in fresh water. So much so, in fact, that their bodies have lost the ability to manufacture urea and -- if placed in full-strength seawater, they quickly die. These freshwater stingrays are thus trapped by their biochemistry

i hope its up to the mark!!!

2007-03-15 06:13:37 · answer #6 · answered by melovedogs 3 · 0 2

Not sure, I could't get any shark in my aquarium.

2007-03-15 06:47:05 · answer #7 · answered by Expression 5 · 0 1

ya they live in fresh and old water..

2007-03-15 06:04:37 · answer #8 · answered by Anonymous · 0 2

no

2007-03-15 06:00:11 · answer #9 · answered by yesette 4 · 0 1

no .

2007-03-17 00:51:11 · answer #10 · answered by Anonymous · 0 1

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