freshwater fish
A freshwater fish is the fish which can live with fresh water.
Even if I do not spend life in fresh water, a thing, a striped mullet or a sea bass spending 1:00 period of the life in seawater like an eel and a sweetfish include the thing which even a saltwater fish originally invades in sea mingled with fresh water area and fresh water in a freshwater fish.
Of these, I call the first thing which does not leave the fresh water area at all with a freshwater fish or a pure freshwater fish and call it with a thing second freshwater fish going into fresh water from sea mingled with fresh water area and the seawater area.
The temporal fish are called about 25,000 kinds, but the freshwater fish is 10,000 and I make it the number of the kinds and reach 40%.
Because it cannot pass seawater level, as for the primary freshwater fish, it is difficult to go out of the water system which ranged with fresh water.
It is rare that I move to the other rivers except introduction by the hand of the person as far as there is not confluence, and there is much hereditary variation by the area.
In addition, I have a long history that was fresh water area, and many endemic species are seen in Lake Biwa-ko or Lake Baikal in the big area of the scale like so-called ancient lake.
It is said that there is more number of the kinds of the fish of the Amazon than the Atlantic whole.
Therefore, the pure freshwater fish has many things that the distribution is not wide.
In addition, those distribution strongly takes influence of the geographical book.
The isolation distribution of the freshwater fish has many examples which must think about influence of the geographical book.
For example, the example that a scale is the biggest is dipnoan fish, and there is the independent genus in Africa of the Southern Hemisphere, Australia, South America by one genus each.
It is thought that these have the origin in this continent having been not separated by water as Gondwana land.
Even if I do not spend life in fresh water, a thing, a striped mullet or a sea bass spending 1:00 period of the life in seawater like an eel and a sweetfish include the thing which even a saltwater fish originally invades in sea mingled with fresh water area and fresh water in a freshwater fish.
Of these, I call the first thing which does not leave the fresh water area at all with a freshwater fish or a pure freshwater fish and call it with a thing second freshwater fish going into fresh water from sea mingled with fresh water area and the seawater area.
The temporal fish are called about 25,000 kinds, but the freshwater fish is 10,000 and I make it the number of the kinds and reach 40%.
Because it cannot pass seawater level, as for the primary freshwater fish, it is difficult to go out of the water system which ranged with fresh water.
It is rare that I move to the other rivers except introduction by the hand of the person as far as there is not confluence, and there is much hereditary variation by the area.
In addition, I have a long history that was fresh water area, and many endemic species are seen in Lake Biwa-ko or Lake Baikal in the big area of the scale like so-called ancient lake.
It is said that there is more number of the kinds of the fish of the Amazon than the Atlantic whole.
Therefore, the pure freshwater fish has many things that the distribution is not wide.
In addition, those distribution strongly takes influence of the geographical book.
The isolation distribution of the freshwater fish has many examples which must think about influence of the geographical book.
For example, the example that a scale is the biggest is dipnoan fish, and there is the independent genus in Africa of the Southern Hemisphere, Australia, South America by one genus each.
It is thought that these have the origin in this continent having been not separated by water as Gondwana land.