A diverse range of fish, reptiles, and amphibians make up the world's freshwater species. Though the majority of the thousands of animal species found in freshwater sources are fish, many amphibian and reptile species also make up the freshwater community. Several mammal, bird, and insect species can also be found living fully or partially in freshwater.
Fishermen may be familiar with the vast array of fish species found in freshwater sources. Dozens of species of corydoras and catfish thrive in these communities. Many different types of pleco fish also live in freshwater. Suckermouth fish, from larger catfish varieties to the dwarf versions captured for aquarium use, live in rivers and streams.
Many different types of squeaker, hatchetfish, and syno fish can be found in freshwater. The popular tetra fish that people enjoy keeping as pets are freshwater fish. Some shark species, such as the bull shark, can live in freshwater. They usually return to saltwater, however, to breed. Certain river sharks, found mostly in Asia and Australia, can fully live and breed in freshwater. The Speartooth shark and Irrawaddy River Shark are two examples.
Like freshwater fish, many reptile and amphibian freshwater species are often caught to be kept as pets. Turtles, such as the red-eared slider, are commonly discovered and kept as such. Some endangered species, such as the striped legless lizard, also live in freshwaters. Frogs, such as the African dwarf and clawed varieties, often make their homes in ponds, streams, and other inland waters. Salamanders and newts, also popular pet choices, typically live in these habitats as well.
Several freshwater species of insects provide food for many of the other freshwater animals. Many of these species, such as the common fly, dragon fly, and mosquito, make their homes in freshwater areas. Water striders and spiders can also be found in these habitats. Many other invertebrates, such as worms and leeches, are also freshwater species.
Most mammals do not live fully immersed within water. The dolphin and manatee, however, are two mammalian species that can live fully in fresh water. Marshes are home to many mammal species, including the muskrat and nutria. Beavers, otters, and platypuses, also mammals, spend much of their time in freshwater as well.
Freshwater bird species often hail from marshy areas. The crane is one of the most well-known freshwater birds. Other avian freshwater species include egrets, herons, woodpeckers, and some types of eagles and hawks.