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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

Ancient fish

Coelacanths, lungfish, sturgeons, gars, bichirs and lampreys. 37 fish on EveryFish so far.

Ancient fish is a loose name for the living members of very old lineages: lampreys and hagfish, which have no jaws; sturgeons and paddlefish; gars, bowfin and bichirs, with their heavy armoured scales; and the lobe-finned coelacanths and lungfish, close relatives of the first animals to walk on land. Together they number only a few hundred species, but they record the deep history of fish.

Coelacanths and lungfish

The coelacanth was known only from fossils and thought extinct for about 66 million years until a fisherman's catch was recognised off South Africa in 1938. A second species was found in Indonesia in 1997. Both live in deep, rocky slopes and give birth to live young. The six lungfish species, in Africa, South America and Australia, breathe air with true lungs, and African lungfish survive dry seasons buried in mud.

The sturgeon crisis

Sturgeons are large, armoured fish of the rivers and coasts of the Northern Hemisphere, many over a century old when caught. Their roe is caviar. Dams, overfishing and poaching have brought most of them close to extinction, and in 2022 the IUCN found every one of the remaining sturgeon species threatened, while declaring the Chinese paddlefish extinct. Lampreys, by contrast, include the sea lamprey, a parasite that became invasive in North America's Great Lakes.

Famous ancient fish

West Indian Ocean coelacanthRediscovered alive in 1938Indonesian coelacanthThe second species, found in 1997Australian lungfishOne of the oldest living vertebrate speciesMarbled lungfishSurvives dry seasons in mudSenegal bichirThe Senegal bichirSea lampreyA jawless parasite of other fish

Still to be written: Beluga (sturgeon), Alligator gar.

Further reading

WaterRivers and lakesEstuaries and mangrovesCoasts and shelvesCoral reefsOpen oceanDeep seaPolar and cold seasCaves and springsBetween sea and river
UseFood fishFarmedAquarium fishSport fishingCulture and faithVenomous or dangerousInvasiveScience and research
OrderBest knownA to ZOldest firstNewest firstBy size
🇺🇸 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 🇷🇺 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 🇲🇽 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 WorldLamprey Jawless fish with a sucking mouth found in temperate waters worldwide.Ancient · Rivers and lakes 🇳🇬 NigeriaGymnarchus African electric fish with a long dorsal fin used for swimming and sensing prey.Ancient · Rivers and lakes · 1829 🇺🇸 United StatesAmerican paddlefish Ancient freshwater fish with a sensory snout and filter-feeding habits.Ancient · Rivers and lakes · 1792 🇧🇷 Brazil and 1 moreArapaima Large freshwater fish from the Amazon basin known for its size and air-breathing ability.Ancient · Rivers and lakes 🇸🇳 Senegal and 3 moreWest African lungfish Air-breathing freshwater fish from AfricaAncient · Rivers and lakes 🇷🇺 Russia and 4 moreSiberian sturgeon Large freshwater sturgeon native to Siberian riversAncient · Rivers and lakes 🇦🇴 Angola and 3 moreMarbled lungfish African lungfish with the largest known animal genome, found in East and Central Africa.Ancient · Rivers and lakes 🇨🇳 ChinaChinese paddlefish A giant freshwater predator from China that is now extinct.Ancient · Rivers and lakes · 1862 🇺🇸 United States and 1 morePacific lamprey An anadromous parasitic jawless fish found along the Pacific Rim.Ancient · Rivers and lakes · 1872

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.