Rivers and lakes
Fresh water: rivers, streams, lakes and ponds. 130 fish on EveryFish so far.
Rivers, lakes, streams and ponds hold less than one per cent of the Earth's water, yet about half of all known fish species live in them. Fresh water is broken into separate basins, and fish that cannot cross between them evolve apart, which is why each river system and lake has its own species. The Amazon, Congo, Mekong and Ganges basins and the great lakes of Africa are the richest.
Life in fresh water
A freshwater fish is saltier inside than the water around it, so it must pump salt in through its gills and pass a lot of dilute urine. Freshwater habitats range from torrential Himalayan streams, where loaches cling to rocks, to warm, still swamps where air-breathing snakeheads, catfish and gouramis thrive. Many river fish time their spawning to floods: the Indian major carps spawn in the monsoon floodwaters, and Mekong fish move into flooded forests.
The most threatened fish
Freshwater fish are declining faster than sea fish. A 2021 report by conservation groups found that about a third of freshwater fish species are threatened with extinction and that 80 had already been declared extinct. Dams block migrations, water is drawn off for farms and cities, pollution and sand mining degrade rivers, and introduced species such as tilapia and African catfish compete with native fish. In India, the rivers of the Western Ghats and the North-East hold many endemic fish at risk.
Famous rivers and lakes fish
Still to be written: Mekong giant catfish.
Further reading
🇪🇬 Egypt and 4 moreNile tilapia
A hardy cichlid farmed globally for food.Cichlid · Rivers and lakes · 1758
🇮🇳 India and 4 moreRohu
A large silver carp from South Asian rivers, farmed for food and prized as a game fish.Carp · Rivers and lakes
WorldNile perch
Large freshwater predator native to Africa, now invasive in many lakes.Other · Rivers and lakes
🇿🇦 South Africa and 4 moreAfrican sharptooth catfish
Large airbreathing catfish farmed across Africa and AsiaCatfish · Rivers and lakes
🇷🇺 RussiaSterlet
A small Eurasian sturgeon found in rivers flowing to the Black, Azov, and Caspian seas.Ancient · Rivers and lakes · 1758
🇺🇸 United StatesShovelnose sturgeon
Smallest North American freshwater sturgeon, known for its shovel-shaped snout and caviar production.Ancient · Rivers and lakes · 1820
🇺🇬 Uganda and 2 moreSilver cyprinid
A small pelagic fish from Lake Victoria that supports regional food security.Other · Rivers and lakes
🇺🇬 UgandaNangnang fish
A small freshwater fish from the Nile basin, prized as a fried snack in Uganda.Other · Rivers and lakes
🇧🇷 Brazil and 3 moreTambaqui
A large freshwater fish from South America known for its heavy body and seed-eating habits.Other · Rivers and lakes
WorldSnakehead
Elongated freshwater predators with air-breathing organs found in Asia and Africa.Other · Rivers and lakes
🇧🇷 Brazil and 1 moreArapaima
Large freshwater fish from the Amazon basin known for its size and air-breathing ability.Ancient · Rivers and lakes
🇷🇺 Russia and 4 moreSiberian sturgeon
Large freshwater sturgeon native to Siberian riversAncient · Rivers and lakes
Southeast AsiaGiant snakehead
A large freshwater predator from Southeast Asia known for air breathing and invasive potential.Other · Rivers and lakes
🇨🇳 China and 1 moreMandarin fish
Freshwater predatory perch native to East AsiaPerch-like · Rivers and lakes · 1855
🇦🇴 Angola and 3 moreMarbled lungfish
African lungfish with the largest known animal genome, found in East and Central Africa.Ancient · Rivers and lakes
🇧🇷 Brazil and 4 moreArapaima
Giant air-breathing freshwater fish of the AmazonOther · Rivers and lakes · 1822
🇨🇳 China and 3 moreAsian swamp eel
A freshwater, air-breathing fish native to Asia and introduced elsewhere.Eel · Rivers and lakes
🇯🇵 JapanNigorobuna
Wild carp from Lake Biwa used for fermented sushi.Carp · Rivers and lakes
🇦🇷 Argentina and 4 moreArgentinian silverside
A large, adaptable silverside native to South America.Other · Rivers and lakes
🇺🇸 United States and 4 moreMosquitofish
Small North American fish introduced globally for mosquito control.Livebearer · Rivers and lakes
🇺🇸 United StatesEastern mosquitofish
A small livebearing fish native to the eastern US, now invasive in many regions.Livebearer · Rivers and lakes · 1859
🇧🇷 Brazil and 1 moreRed-bellied Pacu
A large South American freshwater fish related to piranhas, farmed for food and kept in aquariums.Other · Rivers and lakes
Photo credits on this page
The small pictures above come from Wikimedia Commons under free licences. Some are cropped to fit.
- Nile tilapia: Bjørn Christian Tørrissen, CC BY-SA 3.0, source
- Rohu: Wiki Farazi, CC0, source
- Nile perch: Pavel Zuber, CC BY-SA 3.0, source
- African sharptooth catfish: Unknown author, Public domain, source
- Sterlet: Karelj, Public domain, source
- Shovelnose sturgeon: Kbh3rd, CC BY-SA 4.0, source
- Silver cyprinid: Boulenger, George Albert; Loat, L., Public domain, source
- Nangnang fish: Africalli, CC BY-SA 4.0, source
- Tambaqui: w_endo, CC0, source
- Snakehead: Sir Francis Day, Public domain, source
- Arapaima: This illustration was made by Citron You must credit this : Citron / C, CC BY-SA 3.0, source
- Zebrafish: Roundish, CC0, source
- Siberian sturgeon: This illustration was made by Citron You must credit this : Citron / C, CC BY-SA 3.0, source
- Giant snakehead: George Chernilevsky, Public domain, source
- Mandarin fish: Andshel, CC BY-SA 3.0, source
- Marbled lungfish: George Berninger Jr., CC BY-SA 4.0, source
- Arapaima: George Chernilevsky, Public domain, source
- Golden mahseer: Khalid Mahmood, CC BY-SA 4.0, source
- Asian swamp eel: Leo G. Nico, USGS, Gainesville, FL, Public domain, source
- Nigorobuna: Unknown author, CC BY-SA 2.5, source
- Argentinian silverside: CHUCAO, CC BY-SA 3.0, source
- Mosquitofish: NOZO, CC BY-SA 3.0, source
- Eastern mosquitofish: JeffreyGammon, CC BY-SA 4.0, source
- Red-bellied piranha: Gregory Moine, CC BY 2.0, source
- Red-bellied Pacu: Omnitarian, CC BY-SA 3.0, source