Rivers and lakes
Fresh water: rivers, streams, lakes and ponds. 113 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, Red-bellied piranha.
Further reading
🇺🇸 United States and 4 moreSea lamprey
A jawless, parasitic fish native to the Northern Hemisphere that attacks other fish.Ancient · Rivers and lakes · 1758
🇦🇺 AustraliaLungfish
Ancient freshwater fish that breathe air and have lobed fins.Ancient · Rivers and lakes
🇺🇸 United States and 1 moreShortnose sturgeon
A small, endangered North American sturgeon with a short snout.Ancient · Rivers and lakes · 1818
🇺🇸 United StatesShovelnose sturgeon
Smallest North American freshwater sturgeon, known for its shovel-shaped snout and caviar production.Ancient · Rivers and lakes · 1820
🇧🇯 Benin and 4 moreSaddled bichir
A large African freshwater fish with primitive lungs and multiple dorsal finlets.Ancient · Rivers and lakes · 1845
WorldLeopard bush fish
A freshwater labyrinth fish from the Congo River basin kept in home aquariums.Other · Rivers and lakes
🇰🇪 Kenya and 4 moreRipon barbel
A large freshwater cyprinid from East African lakes and rivers.Carp · Rivers and lakes · 1900
WorldHaplochromis
A large ray-finned fish genus from East Africa known for rapid evolution and aquarium popularity.Cichlid · Rivers and lakes · 1888
🇲🇼 Malawi and 2 moreMalawi eyebiter
Predatory cichlid from Lake Malawi known for its narrow body and unique feeding habits.Cichlid · Rivers and lakes
🇺🇸 United StatesSpotted bass
A North American freshwater fish known for dark spots below its lateral line.Other · Rivers and lakes
🇺🇸 United States and 2 moreGreen sunfish
A small, aggressive freshwater fish native to North America, known for its blue-green colour and invasive potential in nPerch-like · Rivers and lakes
🇺🇸 United States and 1 moreSauger
A freshwater perch species native to North American rivers.Perch-like · Rivers and lakes · 1834
🇸🇷 Suriname and 2 moreRedeye piranha
A large freshwater fish from South America with a rhombus-shaped body and red eyes.Other · Rivers and lakes · 1766
🇧🇷 Brazil and 4 moreWolf fish
A predatory freshwater ray-finned fish found across Central and South America.Other · Rivers and lakes
🇨🇦 Canada and 1 moreBigmouth buffalo
A long-lived North American freshwater fish known for its terminal mouth and exceptional lifespan.Catfish · Rivers and lakes
Photo credits on this page
The small pictures above come from Wikimedia Commons under free licences. Some are cropped to fit.
- Sea lamprey: Fernando Losada Rodríguez, CC BY-SA 4.0, source
- Rohu: Wiki Farazi, CC0, source
- Nile perch: Pavel Zuber, CC BY-SA 3.0, source
- African sharptooth catfish: Unknown author, Public domain, source
- Sockeye salmon: Timothy Knepp of the Fish and Wildlife Service., Public domain, source
- Sterlet: Karelj, Public domain, source
- Lake sturgeon: USFWS Mountain-Prairie, Public domain, source
- Lungfish: Unknown author, CC BY-SA 2.5, source
- Atlantic sturgeon: Jiaqian AirplaneFan, CC BY 3.0, source
- Shortnose sturgeon: Unknown author, Public domain, source
- Kaluga: あおもりくま(Aomorikuma), CC BY-SA 3.0, source
- Shovelnose sturgeon: Kbh3rd, CC BY-SA 4.0, source
- Longnose gar: USFWS Mountain-Prairie, Public domain, source
- Pallid sturgeon: USFWS Fish and Aquatic Conservation, Public domain, source
- Tropical gar: AlejandroLinaresGarcia, CC BY-SA 3.0, source
- Gar: Unknown author, Public domain, source
- Saddled bichir: Studdart, CC BY-SA 3.0, source
- Bichir: 5snake5, CC0, source
- Lamprey: Tiit Hunt, CC BY-SA 3.0, source
- Mooneye: Kevmin, CC BY-SA 3.0, source
- Mawsonia: Ghedoghedo, CC BY-SA 3.0, source
- African tigerfish: Totti, CC BY-SA 4.0, source
- Knightia: Wilson44691, CC0, source
- Gymnarchus: Wiki-Harfus ; modified by Wildfeuer, CC BY-SA 3.0, source
- Silver cyprinid: Boulenger, George Albert; Loat, L., Public domain, source
- Nile bichir: Boulenger, George Albert; Loat, L., Public domain, source
- Leopard bush fish: Zaire, CC BY-SA 3.0, source
- Nangnang fish: Africalli, CC BY-SA 4.0, source
- Synodontis: Paweł Cieśla Staszek_Szybki_Jest, CC BY-SA 4.0, source
- Ripon barbel: Georges Albert Boulenger, Public domain, source
- Haplochromis: User:Haplochromis, CC BY-SA 3.0, source
- Malawi eyebiter: Gareth J. Fraser, C. Darrin Hulsey, Ryan F. Bloomquist, Kristine Uyesu, CC BY 2.5, source
- Largemouth bass: Totti, CC BY-SA 4.0, source
- Spotted bass: Unknown author, Public domain, source
- Guadalupe bass: Nick Loveland, CC0, source
- Pumpkinseed: Cephas, CC BY-SA 3.0, source
- Black crappie: USFWS Mountain-Prairie, Public domain, source
- Green sunfish: Duane Raver, Public domain, source
- Muskellunge: Engbretson, Eric / U.S. Fish and Wildlife Service, Public domain, source
- Sauger: Duane Raver, Public domain, source
- Redeye piranha: Torox, CC BY-SA 3.0, source
- Tambaqui: w_endo, CC0, source
- Desert pupfish: jkirkhart35, CC BY 2.0, source
- Mexican tetra: User:Haplochromis, CC BY-SA 3.0, source
- Wolf fish: J. F. Hennig, Public domain, source
- White sucker: Brian Gratwicke, CC BY 2.0, source
- Bigmouth buffalo: Unknown author, Public domain, source
- Delta smelt: Peterson, B. Moose / U.S. Fish and Wildlife Service, 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
- Golden mahseer: Khalid Mahmood, CC BY-SA 4.0, source
