Grayling

Identification

The grayling is an elegant fish with a strikingly large, tall dorsal fin that can be raised like a flag. This dorsal fin is reddish-purple to violet with rows of dark spots — unique among European freshwater fish. The body is slender and silvery with a blue-grey back. Freshly caught fish emit a faint thyme scent, explaining the scientific name Thymallus. Reaches 30 to 50 cm.

Behavior & ecology

The grayling inhabits cool, fast-flowing streams with clean, oxygen-rich water and gravel substrate. Related to trout and salmon but preferring slightly slower current. The diet consists of insects (especially mayflies and caddisflies), both from the bottom and the water surface — making it a classic fly-fishing species.

In the Netherlands

The grayling is extremely rare in the Netherlands. Historically found in streams in southern Limburg (Geul, Gulp), it had virtually disappeared due to water pollution. Our database holds only 39 records. In neighboring countries like Belgium (Ardennes) and Germany (Eifel), the grayling is more common and a valued sport fish for fly fishers.