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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. 142 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

RohuA river carp of the Indian subcontinentArapaimaAn air-breathing giant of the AmazonGolden mahseerThe golden mahseer of Himalayan riversNile perchA huge predator of African lakesRed-bellied piranhaA schooling fish of South American riversZebrafishA small fish of South Asian streams

Still to be written: Mekong giant catfish.

Further reading

GroupSharkRayCarpCatfishSalmonidHerringCodTunaPerch-likeCichlidReef fishEelFlatfishLivebearerAncientOther
UseFood fishFarmedAquarium fishSport fishingCulture and faithVenomous or dangerousInvasiveScience and research
OrderBest knownA to ZOldest firstNewest firstBy size
Southeast AsiaBumblebee goby Small striped freshwater and brackish gobies from AsiaOther · Rivers and lakes WorldSilver dollar Round, silver tropical fish related to piranhas, popular in aquariums.Other · Rivers and lakes 🇨🇳 China and 4 moreCelestial Eye goldfish Fancy goldfish with upward-facing telescope eyesOther · 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 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 WorldBichir Ancient African ray-finned fish with multiple dorsal finlets and lung-like air breathing organs.Ancient · Rivers and lakes 🇧🇼 Botswana and 1 moreAfrican tigerfish Predatory freshwater fish known for sharp teeth and leaping hunting behaviour.Other · Rivers and lakes · 1861 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 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 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 🇧🇷 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 moreMexican tetra A freshwater characin with surface and blind cave forms, studied for evolutionary biology.Other · Rivers and lakes 🇹🇭 Thailand and 3 moreSiamese tigerfish A critically endangered freshwater perch from Indochina.Perch-like · Rivers and lakes · 1998 🇧🇷 BrazilBanded leporinus A striped freshwater fish from the Amazon kept in home tanks and occasionally caught by anglers.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 🇮🇳 India and 4 moreZebrafish Small striped fish from South Asia kept in aquariums and labsCarp · Rivers and lakes WorldFeatherbacks and knifefishes Freshwater bony-tongued fishes with long anal finsOther · Rivers and lakes Southeast AsiaGiant snakehead A large freshwater predator from Southeast Asia known for air breathing and invasive potential.Other · Rivers and lakes 🇹🇭 Thailand and 2 moreSiamese mud carp Freshwater cyprinid native to Mekong and Chao Phraya riversCarp · Rivers and lakes WorldAphyosemion A large genus of small African killifish kept in home aquariums.Livebearer · Rivers and lakes 🇺🇸 United States and 2 moreBluegill A common North American sunfish known for its blue gill covers and popularity with anglers.Perch-like · Rivers and lakes · 1854 🇧🇷 Brazil and 4 moreArapaima Giant air-breathing freshwater fish of the AmazonOther · Rivers and lakes · 1822 WorldDanio A genus of small striped freshwater fish from Asia kept in aquaria.Other · Rivers and lakes · 1822 WorldRasbora A diverse genus of small freshwater fish native to South and Southeast Asia.Carp · Rivers and lakes · 1822 🇲🇽 Mexico and 3 moreXiphophorus A genus of small livebearing fish native to Mexico and Central America, known for aquarium use and genetic research.Livebearer · Rivers and lakes 🇦🇺 Australia and 2 moreRainbowfish Small colourful freshwater fish from Australia and New GuineaOther · Rivers and lakes · 1894 WorldKillifish Small egg-laying fish known for hardiness and short lifespansLivebearer · Rivers and lakes WorldArowana Freshwater bony fish with a toothed bone in the mouth and air-breathing ability.Ancient · Rivers and lakes · 1831 🇺🇸 United StatesLeast killifish A tiny North American fish that gives birth to live young and measures just two centimetres long.Livebearer · Rivers and lakes 🇯🇵 JapanJapanese rice fish Small freshwater fish native to Japan and a key model organism.Other · Rivers and lakes 🇧🇷 Brazil and 1 moreLargescale four-eyes Surface-dwelling fish with split eyes for dual vision.Livebearer · Rivers and lakes · 1758 🇧🇷 Brazil and 4 moreRed-bellied piranha A widespread South American freshwater fish known for its omnivorous diet and shoaling behavior.Other · Rivers and lakes 🇧🇷 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 🇲🇽 MexicoButterfly splitfin A critically endangered livebearing fish from Mexico.Livebearer · Rivers and lakes · 1971 WorldHeadstander South American freshwater fish known for swimming with their heads pointed downwards.Other · Rivers and lakes 🇨🇳 ChinaButterfly loach A small, flat freshwater loach from fast Chinese streams.Other · Rivers and lakes 🇰🇭 Cambodia and 4 moreGyrinocheilus aymonieri A Southeast Asian freshwater fish known for its suction-like mouth and role in the aquarium trade.Other · Rivers and lakes 🇨🇳 ChinaTelescope goldfish Fancy goldfish breed with large protruding eyesCarp · Rivers and lakes 🇯🇵 JapanRanchu A hooded goldfish breed from Japan with no dorsal fin and a rounded body.Other · Rivers and lakes WorldTetra Common name for small freshwater characiform fishes popular in aquaria.Livebearer · Rivers and lakes 🇧🇷 BrazilBlack arowana A South American freshwater fish known for its dark colour and jumping hunting style.Other · Rivers and lakes 🇮🇩 Indonesia and 4 moreAsian arowana Large freshwater fish from Southeast Asia known for its metallic scales and cultural significance.Ancient · Rivers and lakes · 1840 🇵🇦 Panama and 1 moreGlass knifefish Translucent electric fish from South American riversOther · Rivers and lakes
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