Common alder can be found along riversides, and in fens and wet woodlands. Its exposed roots provide shelter for fish, and its rounded leaves are food for aquatic insects.

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 fearsome common backswimmer hunts insects, tadpoles and fish. It uses its oar-like legs to swim upside-down under the water's surface where unsuspecting prey can be found.

The common carp is a very large fish that is popular with anglers due to its size and fighting spirit. It frequents ponds, gravel pits and lakes, but is not native to the UK, being introduced in…

A diminutive but aggressive predator, the three-spined stickleback hunts tadpoles and small fish. It is also known for fiercely protecting its nest of eggs until they hatch. Look for it in ponds,…

The gudgeon is a bottom-dwelling fish, similar to the stone loach, but with only two whisker-like barbels near its mouth. These sensory organs help it to find its prey in the sand and gravel of…

Guillemots really know how to live life on the edge – quite literally! They nest tightly packed on steep ledges and cliffs around the coast. This may sound like a strange nesting spot, but it…

The streamlined red-breasted merganser is a handsome bird and a great fisher - its long, serrated bill helps it to catch and hold its slippery fish prey. It is most commonly spotted around the…

The streamlined goosander is a handsome bird and a great fisher - its long, serrated bill helps it to catch and hold its slippery fish prey. It nests in riverbank trees, but can be seen on lakes…

This little fish is found in rockpools during the summer months and has a clever adaptation that stops it being swept away by strong waves - their pelvic fins are fused to form a sucker that it…