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Fresh water fish species

Fresh water fish types Fresh water fish are fish that spend some or all of their lives in fresh water, such as rivers and lakes, with a salinity of less than 0.05 percent. These environments differ from marine conditions in lots of ways, the most obvious being the difference in levels of salinity. To survive in fresh water, the fish need a range of physiological adaptations in order to keep the ion concentration of their bodies balanced. 41 percent of all known species of fish are found in fresh water. This is primarily due to the rapid speciation that the scattered habitats make possible. When dealing with ponds and lakes, one may use the same basic models of speciation as when studying island biogeography.

Lot of species of fish do reproduce in fresh water, but spend most of their adult lives in the sea. These are known as anadromous fish, and include, for instance, salmon, trout and three-spined stickleback. Some other kinds of fish are, on the contrary, born in salt water, but live most of or parts of their adult lives in fresh water; for instance the eels.

Species migrating between marine and fresh waters need adaptations for both environments; when in salt water they need to keep the bodily salt concentration on a level lower than the surroundings, and vice versa. Many species solve this problem by associating different habitats with different stages of life. Both eels, anadromous salmoniform fish and the sea lamprey have different tolerances in salinity in different stages of their lives.

Fresh water fish differ physiologically from salt water fish in several aspects. Their gills must be able to diffuse water while simultaneously keeping the salts of the bodily fluids inside. The scales of the fish also plays a part in the scientific process; fresh water fish that have lost too many scales get a surplus of water diffused in through the skin, causing the fish to die.

Freshwater fish in florida:

Florida has 3 million acres of fresh water lakes and 12,000 miles of streams and rivers. From those waters over 250 different species of fresh water fishes have been collected. This includes several rather rare native fishes and 73 species of non-native fishes (fish that come from outside of the United States and would not have been found in Florida if it were not for man's intervention). Another trait characteristic of fresh water fish are the well developed kidneys. These have to be large because a lot of water passes through them.

The fish species that most people tend to think about are the larger fish that are used for recreation or food. Of those, the 33 most popular are part of the Florida Fish and Wildlife Conservation Commission's (FWC) "Big Catch" program and most are described in detail in this section of our web site (click the group you want to learn about in the table above, or if you aren't certain of the group in which to find a fish you can pick it from the common names list). There is also a poster (small pdf version available for download) that illustrates these fishes and is available for schools and fishing-related businesses that will publicly display it. A separate brochure is available to identify some of Florida's common exotic fishes

About four in ten North American fresh water fish are endangered, according to a pan-North American study. The main cause being human pollution. The number of fish species and subspecies to become has risen from 40 to 61, since 1989