Common name: Grayling
Latin name: Thymallus thymallus
Record weight: Despite a record weight of only 4lb 3oz, caught in 1989 by Mr S.R. Lanigan, the grayling is known to grow much larger than this in Europe. Fish of almost ten pounds are possible in some rivers in Northern Europe!
Distribution: Found in the more mountainous areas across Europe where it thrives in small fast flowing streams with high water quality and cool water. Absent from Northern Scotland and Ireland.
Features: The unmistakable huge dorsal fin of the grayling sets it apart from all other salmonid species. The sail-like dorsal is almost as high as the depth of the fish and extends for one third of the fish's length. Like all salmonids the grayling has a small adipose fin behind the dorsal fin. The grayling has a slightly underslung mouth and steely blue/purple colouration
Diet: Grayling adore caddis larvae and eat them in very large quantities. Despite their underslung mouths, they are quite capable of feeding upon drifting prey, which they tip up to capture. As with most fish found in small streams, grayling mainly feed at dawn and dusk. Large grayling are known to feed upon small fish, and in Scandinavian countries spinning with tiny lures is a recognised method for catching these sporting fish.
Spawning: Grayling spawn around the beginning of March in the UK, although in Northern areas this may be delayed by as much as two months. Like all salmonids, grayling spawn on clean gravel, excavating a small redd in the gravel in which their eggs are laid. Clean gravel with a good exchange of water is essential for the survival of grayling eggs as they are very susceptible to pollution. Adult grayling are not particularly fecund and only produce around 10,00 eggs.
Growth: Grayling spend their first month of life within the gravel, first using up the food reserves in their yolk sack, and then actively hunting small invertebrates that live between the particles of gravel. Once they emerge from the gravel, grayling grow extremely rapidly, reaching a length of around four inches by the end of their first year. The young fish mature within three years at a length of around eight inches. Grayling are not a long-lived fish and rarely live for more than eight to ten years. In very rich streams, where they grow more rapidly, they may only live for four to five years.