‘Killer’ shrimps

‘Killer’ shrimp is the worst non-native invader of England and Wales’ waterways, says the Environment Agency.

Known as Dikerogammarus villosus, it kills native shrimp and young fish.

The Environment Agency’s worst 10 alien invaders include water primrose, giant hogweed and Japanese knotweed which can damage riverbanks and buildings.

The agency said invasive species cost the UK about