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Photo by Bruce Bonebrake
Photo Copyright Bruce Bonebrake
Arctic Grayling
Thymallus arcticus
NatureServe conservation status
Global (G-rank): G5
State (S-rank): SNA
External links
General information
The arctic grayling, Thymallus arcticus, is beautiful sport fish that is easily recognizable due to its large sail-like dorsal fin. The arctic grayling is holarctic in distribution, which means that the species occurs in the northern parts of North America, Europe, and Asia. The arctic grayling is not native to Utah, but it has been introduced into several high elevation lakes in the Uinta Mountains.
The arctic grayling eats primarily invertebrates, including insects, insect larvae, and zooplankton. The species spawns in streams during the early spring, and eggs hatch in two to three weeks. Arctic grayling prefer clear cold water and the species does best in streams and lakes containing at least some aquatic vegetation.
Species range
Holarctic. Northern Eurasia and North America. North America: widespread in Arctic drainages from Hudson Bay west to Alaska, and in Arctic and Pacific drainages south to central Alberta and British Columbia; upper Missouri River drainage, Montana. Formerly in rivers flowing into lakes Michigan, Huron, and Superior, northern Michigan (now extirpated). Introduced widely in western North America south to California, Arizona, and Nevada; locally common (Page and Burr 1991, Lee et al. 1980).
Migration
Migrates up streams in early spring to spawn. Migrates downstream in fall.
Habitat
Open water of clear, cold (47-52 F) medium to large rivers and lakes. Adults move to pools after spawning, spend winter in deep water. Spawning takes place in creeks with gravel-bottomed riffles. Spawning in lakes is rare. Does not construct a redd. Lake populations can spawn in either inlet or outlet streams. At Deer Lake, Montana, most young apparently entered the lake from the outlet stream spawning area during the 6-7-month period of annual ice cover; a small proportion of the fry were lost over a downstream waterfall (Deleray and Kaya 1992). In contrast, young in populations that spawn in inlet streams generally enter lakes much sooner. The extended period of stream residence may be related to avoidance of predation by large conspecifics in Deer Lake (Deleray and Kaya 1992).
Food habits
Oportunistic. Fry feed mainly on zooplankton. Adults feed mainly on terrestrial and aquatic insects (larvae, pupae and adults); also crustaceans, snails, fish eggs, and small fish.
Ecology
Predators probably include other fishes and predatory birds (osprey, gulls, eagles) and mammals (mink, otter).
Reproductive characteristics
Spawns usually in early spring (May-June). Male establishes a territory. Normally lays 400-12,500 eggs (Moyle 1976), which hatch in 11-21 days. Sexually mature in 3-4 years. Lifespan usually less than 6 years but up to 10 years (Brown 1971).
Threats or limiting factors
Localized threats may exist, but on a range-wide scale no major threats are known.
References
- Biotics Database. 2005. Utah Division of Wildlife Resources, NatureServe, and the network of Natural Heritage Programs and Conservation Data Centers.
- Sigler, W. F. and J. W. Sigler. 1996. Fishes of Utah[:] a natural history. University of Utah Press. Salt Lake City. 375 pp.
