Freshwater pearl mussels spend their adult lives anchored to the river bed, filtering water through their gills and improving the quality of the water for other species.

This slender shark gets its name from the spines in front of its dorsal fin. It can use these spines to defend itself by curling in a bow and striking at a predator.

This dainty seaduck is a winter visitor to our coasts, particularly in northern and eastern Scotland.

A delicate wader, Red-necked phalaropes are as comfortable swimming as they are on land. Unusually for birds, the females are more brightly coloured than the males.

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.