A sail-finned salmonid of crystal-clear northern streams, beloved by fly anglers for its iridescent dorsal fin.
Where it lives
Arctic grayling inhabit cold, clear rivers and lakes across the Arctic and sub-Arctic, from Hudson Bay west across Alaska and through Siberia to Mongolia. A small relict population persists in Montana. They favor gravel-bottomed streams and stable lake outlets.
How to recognise it
A streamlined silvery fish with a smattering of small black spots on the forward flanks. The defining feature is the enormous dorsal fin — sail-like, edged in red and dotted with iridescent purple, blue, and green spots, larger and more colorful in males. The body has a faint metallic violet sheen.
Diet & behavior
Grayling are surface-oriented insect feeders, rising readily to mayflies, caddis, and stoneflies on warmer days. They form loose schools and hold position in riffles. Spawning is in spring; no redd is built — eggs are broadcast into gravel.
Fisheries & Conservation
Globally Least Concern. Northern populations remain robust, but southern populations in the lower 48 United States are threatened by warming and habitat loss.