Freshwater Fish

Freshwater fish are fish that spend some or all of their lives in freshwater, such as rivers and lakes, with a salinity of less than 0.05%. In many ways the environment is different from the marine environment, and the most difference is the level of salinity. To survive in fresh water, the fish need physiological adaptations aimed at maintaining the balance of ion concentration in the body.
41% of all fish species known to reside in freshwater. This is due to the rapid speciation that the scattered habitats make it possible to live.

 Freshwater fish differ physiologically to saltwater fish in several aspects. Their gills should be able to diffuse the water while keeping the salt levels in body fluids simultaneously. Adaptation on the part of the fish scales also play an important role; freshwater fish lose scales will get a lot of the excess water that diffuses into the skin, and can cause death in fish.
Other characteristics related to freshwater fish is a well-developed kidneys. The kidneys of freshwater fish are large because a lot of water through it.

Many species reproduce in freshwater but spend most of their lives at sea. They are known as anadromous fish, including salmon, trout, and stickleback. Some fish, in contrast, was born at sea and live in fresh water, such as eels.

Bemigrasi species between sea water and fresh water environments require adaptation at both. When in sea water, they have to keep the concentration of salt in their body is lower than on the environment. Whereas when it is in fresh water, they should keep salt levels were above the concentration of the surrounding environment. Many species solve this problem by associating with different habitats at different stages of life. Eel, salmon nation, and lampreys have a salinity tolerance at different stages of their lives.

Description of freshwater fish will explain a little about freshwater fish that is with photos / pictures (if any). To that end, can click the names of the fish below.

Various Freshwater Fish:

     > Barramundi
     > Koi fish
     > fish Sumatra
     > goldfish
     > Borneo Sucker
     > Betta fish (Betta sp)
     > The guppy (Poecilia reticulata)
     > Catfish (Catfish)
     > fish Belida
     > Spotted Headstander (Chilodus punctatus)
     > Longnose Gar (Lepisosteus osseous)
     > Marlier's Julie (Julidochromis Cyprichromis leptosoma marlieri)
     > Japanese Medaka (oryzae latipes)
     > fish Synodontis
     > Chinese Sturgeon (Acipenser sinensis)
     > Four fish eye / Four Eyed Fish (Anableps anableps)
     > Royal Pleco L190 (Panaque nigrolineatus)
     > Red Tail Barracuda (Acestrorhynchus falcatus)
     > Arctic grayling (Thymallus arcticus)
     > Orino Peacock Bass (Cichla Orinocensis)
     > Glass knifefish (Eigenmannia virescens)
     > Arowana jardini (Scleropages jardini)
     > Red-tailed Red Eye Puffer (Carinotetraodon irrubesco)
     > Palmas fish (Polypterus palmas)
     > African Snakehead (Parachanna obscura)

And many others on this website.