News
RiversEl Niño seen disrupting fish migration patternsSpeciesScientists 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-NicolaRiversEl Niño seen disrupting fish migration patternsSpeciesScientists 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-Nicola
EveryFish

Rivers and lakes

Fresh water: rivers, streams, lakes and ponds. 635 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

Further reading

🇦🇺 AustraliaSouthern saratoga A primitive freshwater fish native to Queensland rivers.Other · Rivers and lakes 🇦🇺 AustraliaMurray River rainbowfish Colourful freshwater fish from southeastern Australia.Other · Rivers and lakes 🇦🇺 AustraliaSpangled grunter Hardy Australian freshwater fish with reddish spotsOther · Rivers and lakes · 1859 🇹🇭 Thailand and 3 moreSnakeskin gourami A large Southeast Asian freshwater fish known for its striped pattern and air-breathing ability.Other · Rivers and lakes 🇮🇩 Indonesia and 4 moreGiant gourami A large freshwater fish from Southeast Asia valued for food and kept in aquaria.Other · Rivers and lakes 🇮🇳 India and 1 moreYoyo loach Freshwater fish with yoyo-shaped markingsOther · Rivers and lakes 🇺🇸 United States and 1 moreStriped bass Anadromous marine fish native to the Atlantic coast of North America, known for sport fishing and culinary use.Other · Rivers and lakes 🇺🇸 United States and 1 moreAlligator gar A large, primitive freshwater fish native to North America known for its armored scales and air-breathing ability.Other · Rivers and lakes · 1803 Latin America and the CaribbeanPayara Predatory Amazonian fish with long lower fangsOther · Rivers and lakes WorldPufferfish Toxic fish that inflate into spiny spheres for defence.Other · Rivers and lakes 🇨🇩 Democratic Republic of the CongoGoliath tigerfish A massive freshwater predator from the Congo River Basin known for its size and sharp teeth.Other · Rivers and lakes · 1898

Photo credits on this page

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

The weekly digest

Every Monday: the fish of the day, new pages on EveryFish, and the conferences and anniversaries of the week ahead.