The grayling is a member of the salmon family but because it spawns at the same time of year as coarse fish it is usually regarded as such. Grayling cannot tolerate pollution and because of this their distribution is restricted to clean, fast-flowing rivers. In rivers where they exist, grayling are generally found in great numbers. In some rivers which are managed as trout waters, grayling are regarded as a pest and removed by their thousands. The extent to which grayling eat trout fry or actually compete with trout for food is very arguable, especially since most trout rivers are now artilically stocked with mature trout.
The grayling is a handsome fish with a vividly marked, sail-like dorsal fin. The eyes of the grayling are pear shaped and large. Although not long-lived, grayling grow very quickly during their first few years and can reach a length of I 1 inches (27-9 cm) in 2 years. The mouth of the grayling is underneath a pointed snout and rather suggests that it is adapted to feeding on the river bed. This is somewhat misleading because grayling do rise readily to take Hies from the surface of the river. Grayling spawn in early spring and the eggs are large and sticky so that they lodge in the gravel on the river bed.