Freshwater fish

Freshwater fish are fish species that spend some or all of their lives in freshwater, such as rivers and lakes, with a salinity of less than 0.05%. These environments differ from marine conditions in many ways, the most obvious being the difference in levels of salinity. To survive fresh water, the fish need a range of physiological adaptations.

Physiology of Freshwater Fish

Freshwater fish are able to regulate their osmotic balance via a process known as osmoregulation. This involves the regulation of salt concentrations in the bloodstream. Unlike saltwater fish, which tend to lose water due to the high salinity of their environment, freshwater fish face the opposite problem. They must constantly excrete water in order to maintain their internal salt concentration.

Freshwater Fish Species

There are many species of freshwater fish, including the trout, salmon, and catfish. These species are popular for fishing and aquaculture due to their size and taste. Other species, such as the carp, are often considered pests due to their ability to rapidly reproduce and take over new environments.

Freshwater Fish in Aquaculture

Aquaculture is the farming of fish and other aquatic organisms. Freshwater fish are commonly farmed due to their ability to thrive in a controlled environment. The most commonly farmed freshwater fish include tilapia, catfish, and trout. These species are farmed for their meat, which is a major source of protein for many people around the world.

Threats to Freshwater Fish

Freshwater fish face many threats, including pollution, habitat destruction, and overfishing. These threats can lead to a decrease in fish populations and a loss of biodiversity. Conservation efforts are needed to protect these species and their habitats.

See Also

• Marine fish
• Fish physiology
• Aquaculture
• Fish farming

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• Sturgeon
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• Freshwater fish
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• Greenback Cutthroat Trout
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