One of the most colourful fish in UK seas, the cuckoo wrasse looks like it belongs in the tropics. Don't be fooled though, it's very much a native species.

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.…

An attractive, olive-green bird, the greenfinch regularly visits birdtables and feeders in gardens. Look for a bright flash of yellow on its wings as it flies.

Buddleia is a familiar shrub, well-known for its attractiveness to butterflies. It is actually an introduced species, however, that has become naturalised on waste ground, railway cuttings and in…

The extensive, golden-brown reedbeds that are formed by stands of Common reed are a familiar sight in our wetlands. They provide an important home for many species, including the rare Bittern.

Sand sedge is an important feature of our coastal sand dunes, helping to stabilise the dunes, which allows them to grow up and become colonised by other species.

With a silvery body, and purple, pink and bluish streaks down its flanks, the rainbow trout lives up to its name. Popular with anglers, it is actually an introduced species in the UK.

The common sexton beetle is one of several burying beetle species in the UK. An undertaker of the animal world, it buries dead animals like mice and birds, and feeds and breeds on the corpses.