Freshwater 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%. 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.
41.24% 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 might use the same basic models of speciation as when studying island biogeography.
Read more about Freshwater Fish: Physiology, Migrating Fish
Famous quotes containing the word fish:
“I have often told you that I am that little fish who swims about under a shark and, I believe, lives indelicately on its offal. Anyway, that is the way I am. Life moves over me in a vast black shadow and I swallow whatever it drops with relish, having learned in a very hard school that one cannot be both a parasite and enjoy self-nourishment without moving in worlds too fantastic for even my disordered imagination to people with meaning.”
—Zelda Fitzgerald (1900–1948)