Seasons: January

Famously predatory, the long, slender pike will lurk among the vegetation of a river or lake, bursting out with ferocious speed to catch its prey. Look out for it across the UK.

The silvery chub can be seen gathering in large shoals in lowland rivers and streams. It is a member of the carp family and looks very similar to the dace, but is larger and has redder fins.

The silvery dace can be seen gathering in large shoals in lowland rivers and streams. It is a member of the carp family and looks very similar to the chub, but is smaller.

Living up to its name, the bullhead has a characteristically large, flattened head and a tapering body. Look out for it in fast-flowing, stony rivers and streams.

The stone loach is notoriously hard to spot - not only is it mostly nocturnal, it is also well camouflaged and can partially bury itself in the riverbed. It uses its whisker-like barbels to find its prey.

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.

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.

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.

The Atlantic salmon spends most of its life at sea, but makes an epic journey back to the river or stream in which it hatched to spawn. Look out for it in freshwater rivers in the north and west.

The Yellow slug lives up to its name - its yellow body is mottled with grey patches. Often found in gardens and damp places in houses, it can be considered a pest, but is an important nutrient recycler.