Look for Water avens in damp habitats, such as riversides, wet woodlands and wet meadows. It has nodding, purple-and-orange flowers that hang on delicate, purple stems.

Look for wood avens along hedgerows and in woodlands. Its yellow flowers appear in spring and provide nectar for insects; later, they turn to red, hooked seedheads that can easily stick to a…

The river lamprey is a primitive, jawless fish, with a round, sucker-mouth which it uses to attach to other fish to feed from them. Adults live in the sea and return to freshwater to spawn.

A common and diminutive fish, the minnow can be found in freshwater streams, rivers and lakes across the country. Look out for the dark stripe along its flank and the red bellies of the males.

The White-clawed crayfish is a freshwater, bronze-coloured crustacean with pale undersides to its claws - hence the name. It is under threat from an invasive and introduced species of crayfish.…

A fierce predator of small fish and flying insects, the brown trout is widespread in our freshwater rivers. It is has a golden body, flanked with pale-ringed, dark spots.