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SpeciesScientists Discover Mysterious New Fish in the Red Sea – and Have Never Seen It AgainOceanEye to eye with Britain's hidden sharks at SharkAdemy - OceanographicRiversIn October, biologists surveying a New York harbor for invasive fish pulled up a bright yellow one. It wasn't an invasive species at allOceanShedd Aquarium Sends Shark Eggs to Bolster Wild PopulationsSpeciesA rare fish has been found in Lake Ontario, North America, whose entire body is golden. It is a nati..OceanThe Great Sea Reef Is Fiji’s Wildest Dive, and a New Frontier for ConservationOceanEckerd College professor contributes to designating Biscayne Bay an Important Shark and Ray AreaSpeciesRio Verde Grande Survey Identifies Fifty-Three Fish Species Facing Flow ReductionsFisheriesAdams River Salmon Run in Thompson-NicolaIndiaHilsa production dropped 26% in five years, fisheries minister tells parliamentSpeciesScientists Discover Mysterious New Fish in the Red Sea – and Have Never Seen It AgainOceanEye to eye with Britain's hidden sharks at SharkAdemy - OceanographicRiversIn October, biologists surveying a New York harbor for invasive fish pulled up a bright yellow one. It wasn't an invasive species at allOceanShedd Aquarium Sends Shark Eggs to Bolster Wild PopulationsSpeciesA rare fish has been found in Lake Ontario, North America, whose entire body is golden. It is a nati..OceanThe Great Sea Reef Is Fiji’s Wildest Dive, and a New Frontier for ConservationOceanEckerd College professor contributes to designating Biscayne Bay an Important Shark and Ray AreaSpeciesRio Verde Grande Survey Identifies Fifty-Three Fish Species Facing Flow ReductionsFisheriesAdams River Salmon Run in Thompson-NicolaIndiaHilsa production dropped 26% in five years, fisheries minister tells parliament
EveryFish

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

🇮🇳 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 🇺🇸 United States and 4 moreSea lamprey A jawless, parasitic fish native to the Northern Hemisphere that attacks other fish.Ancient · Rivers and lakes · 1758 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 🇺🇸 United States and 3 moreSockeye salmon Anadromous Pacific salmon known for red spawning colour and zooplankton diet.Salmonid · Rivers and lakes · 1792 🇦🇺 AustraliaLungfish Ancient freshwater fish that breathe air and have lobed fins.Ancient · 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 States and 1 moreLake sturgeon A large, long-lived freshwater fish native to North America.Ancient · Rivers and lakes 🇺🇸 United States and 1 moreAtlantic sturgeon A large anadromous fish native to the western Atlantic Ocean and its river systems.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 🇷🇺 Russia and 2 moreKaluga A massive semi-anadromous sturgeon from the Amur River basin hunted for caviar.Ancient · Rivers and lakes · 1872 🇺🇸 United StatesShovelnose sturgeon Smallest North American freshwater sturgeon, known for its shovel-shaped snout and caviar production.Ancient · Rivers and lakes · 1820 🇺🇸 United StatesPallid sturgeon An endangered North American sturgeon species native to the Missouri and Mississippi river basins.Ancient · Rivers and lakes · 1905 🇺🇸 United States and 2 moreLongnose gar A primitive ray-finned fish with a long snout and armored scales found in North America.Other · Rivers and lakes · 1758 🇲🇽 Mexico and 2 moreTropical gar A small freshwater predator from Central America known for its armored scales and air-breathing ability.Ancient · Rivers and lakes 🇺🇸 United States and 2 moreGar Ancient armored fish with lung-like swim bladders found in North American waters.Ancient · Rivers and lakes · 1758 🇧🇯 Benin and 4 moreSaddled bichir A large African freshwater fish with primitive lungs and multiple dorsal finlets.Ancient · Rivers and lakes · 1845 WorldBichir Ancient African ray-finned fish with multiple dorsal finlets and lung-like air breathing organs.Ancient · Rivers and lakes WorldLamprey Jawless fish with a sucking mouth found in temperate waters worldwide.Ancient · Rivers and lakes 🇺🇸 United StatesMooneye A family of large-eyed North American fish known for their metallic eye shine.Other · Rivers and lakes · 1819 🇧🇷 Brazil and 4 moreMawsonia Extinct giant coelacanth from the Jurassic and Cretaceous periods.Ancient · Rivers and lakes · 1907 🇺🇸 United States and 1 moreKnightia Extinct herring-like fish from the Green River Formation, famous for its abundant fossils.Herring · Rivers and lakes · 1856 🇧🇼 Botswana and 1 moreAfrican tigerfish Predatory freshwater fish known for sharp teeth and leaping hunting behaviour.Other · Rivers and lakes · 1861 🇳🇬 NigeriaGymnarchus African electric fish with a long dorsal fin used for swimming and sensing prey.Ancient · Rivers and lakes · 1829 🇺🇬 Uganda and 2 moreSilver cyprinid A small pelagic fish from Lake Victoria that supports regional food security.Other · Rivers and lakes WorldLeopard bush fish A freshwater labyrinth fish from the Congo River basin kept in home aquariums.Other · Rivers and lakes 🇸🇳 SenegalNile bichir An ancient African fish with lungs and armour-like scales.Ancient · Rivers and lakes 🇺🇬 UgandaNangnang fish A small freshwater fish from the Nile basin, prized as a fried snack in Uganda.Other · Rivers and lakes 🇰🇪 Kenya and 4 moreRipon barbel A large freshwater cyprinid from East African lakes and rivers.Carp · Rivers and lakes · 1900 Sub-Saharan AfricaSynodontis A large African genus of spotted catfish known for squeaking sounds and belly-up swimming.Catfish · Rivers and lakes 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 States and 4 moreLargemouth bass A large freshwater predator native to North America, prized by anglers and invasive in many regions.Other · Rivers and lakes · 1802 🇺🇸 United StatesSpotted bass A North American freshwater fish known for dark spots below its lateral line.Other · Rivers and lakes 🇺🇸 United StatesGuadalupe bass A rare Texas endemic black bass prized by anglers for its fighting spirit.Other · Rivers and lakes 🇺🇸 United States and 2 morePumpkinseed A small freshwater fish native to eastern North America, known for its bright colours and red ear flap.Perch-like · Rivers and lakes · 1793 🇺🇸 United States and 3 moreBlack crappie A spotted freshwater sunfish native to North America, prized by anglers for its sport and table fare.Perch-like · Rivers and lakes · 1856 🇺🇸 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 🇺🇸 United States and 1 moreMuskellunge Large freshwater predatory fish native to North America and the largest member of the pike family.Other · Rivers and lakes 🇸🇷 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 3 moreTambaqui A large freshwater fish from South America known for its heavy body and seed-eating habits.Other · Rivers and lakes 🇧🇷 Brazil and 4 moreWolf fish A predatory freshwater ray-finned fish found across Central and South America.Other · Rivers and lakes 🇺🇸 United States and 1 moreDesert pupfish Small desert fish that survives extreme heat and saltOther · Rivers and lakes · 1853 🇺🇸 United States and 1 moreMexican tetra A freshwater characin with surface and blind cave forms, studied for evolutionary biology.Other · Rivers and lakes 🇺🇸 United StatesWhite sucker A common North American freshwater cypriniform fish with fleshy lips used for bottom feeding.Other · Rivers and lakes · 1803 🇨🇦 Canada and 1 moreBigmouth buffalo A long-lived North American freshwater fish known for its terminal mouth and exceptional lifespan.Catfish · Rivers and lakes 🇺🇸 United StatesDelta smelt A tiny, endangered fish native to California's Sacramento-San Joaquin River Delta.Other · Rivers and lakes · 1963

Photo credits on this page

The small pictures above come from Wikimedia Commons under free licences. Some are cropped to fit.

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