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EveryFish

Estuaries and mangroves

Where rivers meet the sea: estuaries, backwaters and mangroves. 77 fish on EveryFish so far.

Brackish water is the mix of fresh and salt water found in estuaries, lagoons, backwaters and mangrove creeks, where rivers meet the sea. Its saltiness rises and falls with the tides and the seasons, so only fish that can cope with change live there all the time. These waters are rich in food from the land and the sea, and they act as nurseries for many fish that later live on coasts and reefs.

Fish that handle change

Brackish-water fish are euryhaline: they can adjust the salt balance of their bodies as the water changes. Mullets, milkfish, scats, barramundi and the pearlspot live in India's backwaters and lagoons, such as Vembanad in Kerala and Chilika in Odisha. Mudskippers climb out onto mangrove roots at low tide, breathing through their wet skin. Archerfish shoot down insects from overhanging leaves. Bull sharks swim from the sea into estuaries and far up rivers.

Farms and pressures

Coastal ponds that take in tidal water are used to farm fish and shrimp: the bheris of West Bengal, the pokkali fields of Kerala and the milkfish ponds of the Philippines and Indonesia. Estuaries are also where ports, cities and industries crowd, and many are polluted or reclaimed. Clearing mangroves for shrimp farms has removed nurseries for wild fish across tropical Asia, and dams upstream cut the fresh water that keeps estuaries brackish.

Famous estuaries and mangroves fish

MilkfishFarmed in brackish ponds across AsiaBanded archerfishShoots insects from mangrove leaves

Still to be written: Barramundi, Green chromide, Giant mudskipper, Scatophagus argus, Flathead grey mullet, Bull shark.

Further reading

GroupSharkRayCarpCatfishSalmonidHerringCodTunaPerch-likeCichlidReef fishEelFlatfishLivebearerAncientOther
UseFood fishFarmedAquarium fishSport fishingCulture and faithVenomous or dangerousInvasiveScience and research
OrderBest knownA to ZOldest firstNewest firstBy size
🇲🇽 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 WorldKillifish Small egg-laying fish known for hardiness and short lifespansLivebearer · Rivers and lakes 🇺🇸 United StatesLeast killifish A tiny North American fish that gives birth to live young and measures just two centimetres long.Livebearer · Rivers and lakes 🇧🇷 Brazil and 1 moreLargescale four-eyes Surface-dwelling fish with split eyes for dual vision.Livebearer · Rivers and lakes · 1758 🇲🇽 Mexico and 2 moreMexican molly Small livebearing fish from Mexico and Central America.Livebearer · Rivers and lakes 🇺🇸 United States and 1 moreSailfin molly Small livebearing fish with a large dorsal fin in males.Livebearer · Rivers and lakes · 1821 🇲🇽 Mexico and 1 moreGreen swordtail A hardy live-bearing fish popular in home aquariums.Livebearer · Rivers and lakes · 1848

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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