Trout in the classroom

Trout in the classroom

Follow the lifecycle of the brown trout


We are currently offering the ‘trout in the classroom’ project to a limited number of schools in the Chess and Wye catchments. Participating classes recieve an aquarium containing eggs or young fish. The children care for the fish while learning about their life cycle, then release the trout into the local chalk stream. We provide equipment, training, workshops and a river visit. Teachers tell us that the pupils ‘have been so inspired and enthusiastic about the project’ and that taking part has ‘truly sparked an enthusiasm for our local environment amongst the children.’

If you are interested in taking part please contact Education Officer, Ceri Groves –

Brown Trout Lifecycle

The brown trout begins life as an egg. New born trout are called alevins. As they grow alevins become fry, then parr before becoming mature adults when they are 2-4 years old. The amazing change from egg to adult fish is called its lifecycle.

Trout lifecycle poster

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Between November and February male and female brown trout come together to mate.

The female brown trout (hen) digs a nest or redd in the gravel river bed. She does this by turning on her side and flexing her body.

Female trout produce a lot of eggs. The number depends on the size of the fish but can range from high hundreds to several thousands. For example a 500g fish will produce about  800 eggs.



Brown trout eggs stay hidden in the gravel at the bottom of the river. They need a constant supply of cold, clean and well oxygenated water.

Eggs hatch in  30 – 50 days (it takes longer in colder water). The newborn trout are called alevins.

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Newly hatched trout are called Alevins. They remain living in the gravel.

When they are born the yolk sac is still attached to them. They feed off this for the first 2-4 weeks.

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Growing up

When the yolk has been used up the alevin become fry and swim up out of the gravel.

They move towards the light and start to feed on tiny insects in the water

A trout of less than one year old is called a parr. Parr have blue blotches or ‘parr marks’ along their sides which they lose as they get older.

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Brown Trout

Trout become adults, when they are between 2-4 years old. Then the whole lifecycle begins again.

Of the trout that make it to adulthood the average lifespan is about 5 years. Brown trout  can live until they are 20 years old.

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Brown Trout