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LET'S EXPLORE The living world

What lives in rivers, lakes and wetlands?

Trout in a coldwater streamTrout in a coldwater streamA river is a natural channel of water that flows downhill. Near its source, the small river, often called a stream or a brook, flows quickly. Streams eventually join together to form a larger, slower river that flows into a lake or the sea. Both rivers and wetlands, lands that are flooded either permanently or for part of the year, are extremely important habitats for many animals.

River life

A European river in springA European river in springAnimal and plant life in a slow-moving riverAnimal and plant life in a slow-moving riverRivers are home to many plants and animals, both above and below the water. A fast-flowing stream is too rough, but in gentler, deeper water plants can take root in the muddy river bed. They provide food, shelter and nesting sites for many animals. Worms and snails living in the mud are food for fish, which, in turn, are eaten by otters and diving birds such as kingfishers. Mayflies and other insects living near the water’s surface are preyed upon by other insects such as dragonflies. They are also food for birds, fish and frogs.

Mayfly nymphs (young) live underwater for up to two years. When they do finally become adults, they have no mouths so cannot feed. Because of this, they live for as little as a few minutes—or two days at most.

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