Common Name: Arctic Grayling

Synonyms and Other Names:

Identification: Scott and Crossman (1973); Morrow (1980); Page and Burr (1991). Grayling can be distinguished from all other salmonids by the presence of a large, sail-like dorsal fin. At one time T. arcticus was divided into four separate species: T. signifer, T. montanus, T. tricolor, and T. ontariensis. Thymallus signifer is now treated as synonymous with T. arcticus, and the others are considered subspecies of T. arcticus (Lee et al. 1980 et seq.).

Size: 76 cm (Page and Burr 1991)

Native Range: Widespread in Arctic drainages from Hudson Bay to Alaska and in Arctic and Pacific drainages to central Alberta and British Columbia; upper Missouri River drainage, Montana. Formerly in Great Lakes basin, Michigan. Also in Asia (Page and Burr 1991).

The only remaining natural, native remnant population in the continental United States is in Big Hole River, Montana (Wydoski and Whitney 2003). All other populations are the result of introductions or re-introductions.

This map only depicts Great Lakes introductions. Click here for Great Lakes region collection information Click here for the national map

Great Lakes Nonindigenous Occurrences: Grayling have been introduced into Alaska (Morrow 1980); Big Lake and the Salt and Verde drainages in Arizona (Miller and Lowe 1967; Minckley 1973; Lee et al. 1980 et seq.; Rinne 1995); at least 26 waterbodies in 11 counties, including the lower Klamath, Sacramento (Pit), San Joaquin, and northern Mojave drainages in California (Shebley 1917; Dill and Cordone 1997; Moyle 2002); Zimmerman Lake in the Cache la Poudre system, the North and South Platte rivers, the San Luis Valley in the Rio Grande headwaters, the Eagle and Frying Pan rivers on the west slope, and the Arkansas drainage in Colorado (Bowers 1901; Beckman 1952; Everhart and Seaman 1971; Ellis 1974; Morrow 1980; Wiltzius 1985; Zuckerman and Behnke 1986; Walker 1993; Rasmussen 1998); Housatonic drainage in Connecticut (Whitworth 1996); the Kootenai, Spokane, Salmon, Bear, and Snake (above and below the falls) drainages, and other independent drainages in Idaho (Bowers 1901; Linder 1963; Simpson and Wallace 1978; Lee et al. 1980 et seq.; Idaho Fish and Game 1990, 1996, 2012); the Maquoketa and Coon-Yellow systems in Iowa (Bowers 1901); unspecified locations in Maine (Kendall 1914); Ford Lake, Michigan (Hubbs and Lagler 1958); Twin Lake near Isabella in the Rainey headwaters, and several lakes in the Arrowhead region of the Baptism-Brule drainage, including Musquash Lake, Minnesota (Bowers 1901; Eddy and Underhill 1974; Phillips et al. 1982); unspecified locations in Missouri (Pflieger 1971); Glacier National Park, the Belly, Red Rock, Madison, Gallatin, upper Missouri-Dearborn, Sun, Clarks Fork Yellowstone, Pend Orielle, and Rock systems in Montana (Bowers 1901; Lee et al. 1980 et seq.; Cross et al. 1986; Holton 1990; Tilmant 1999); several unspecified streams in Nebraska (Jones 1963; Morris et al. 1974; Cross et al. 1986); high elevation lakes in the northern part of the state, Desert Creek, Ruby Valley, Steele Lake in Elko County, Nevada (Miller and Alcorn 1946; La Rivers 1962; Deacon and Williams 1984; Sigler and Sigler 1987); Long Pond in Benton (Hoover 1936), and Sunapee Lake (Bickford 1914), New Hampshire; the Canjilon area in New Mexico (Koster 1957; Sublette et al. 1990); unspecified areas of New York (Bickford 1914); upper Deschutes (Lee et al. 1980 et seq.) and Umatilla (Bowers 1901) systems, Oregon; the Atlantic basin (Susquehanna and/or Delaware drainage), Pennsylvania (Bean 1892); unspecified areas of South Dakota (Johnson 1937); lakes and streams in Duchesne, Summitt, Cache, and Daggett counties, and in the Uintah and Wasatch mountains, streams near Salt Lake City, Blind, Navajo, Lockawaxen, Caroly, Round, Sand, and Blue lakes, and Red Creek, Big Ells and Labaron reservoirs in Utah (Sigler and Miller 1963; Lee et al. 1980 et seq.; Sigler and Sigler 1987, 1996); Caspian Lake (Bowers 1901) and other unspecified mountainous areas in Vermont (Lee et al. 1980 et seq.; Morrow 1980; Cox, personal communication); below Philpott Reservoir, Virginia (Jenkins and Burkhead 1994); one mountain lake in Washington (Wydoski and Whitney 1979; Fletcher, personal communication); the Namekagon, Wolf, Brule, and Beartrap-Nemadji systems in Wisconsin (Bowers 1901; Becker 1983); and Yellowstone Lake, Bighorn, Wind, and Medicine Bow rivers, Big Sandy Reservoir, Jackson Lake, Babione Creek (upper Tongue), Beartooth Lake (Clarks Fork Yellowstone), and Frye Lake (Popo Agie), Wyoming (Johnson 1937; Baxter and Simon 1970; Lee et al. 1980 et seq.; Cross et al. 1986; DeLorme Mapping 1992; Gorges 1994; Hubert 1994).

Ecology: Grayling generally inhabit clear, cold, high-altitude lakes and rivers (Behnke 2002; Wydoski and Whitney 2003). Spawning occurs in the spring, when water temperatures reach 45-50° F. Unlike most salmonids, grayling do not construct any sort of nest but spawn directly over gravel or rocky areas of smaller streams and tributaries (Behnke 2002). Diet primarily consists of aquatic and terrestrial invertebrates, zooplankton, small fishes, and occasionally fish eggs (Behnke 2002; Wydoski and Whitney 2003).

Means of Introduction: Authorized stocking for sportfishing. First stocked in Arizona in 1943 (Rinne 1995). First stocked in Connecticut in the 1870s (Whitworth 1996). Stocked in Nebraska in 1939 (Jones 1963). First stocked in southern Michigan in 1877 (Fukano et al. 1964).

Status: Established in several states, including Arizona (Rinne 1995). Reported from Colorado, Montana, Nevada, Oregon, and Vermont. Failed in Connecticut, Maine, Missouri, Nebraska, New Mexico, and Virginia. Extirpated from Pennsylvania.  Although largely extirpated from its native range within the Great Lakes basin, it is found in some inland lakes in the region that were not part of its original range.

Great Lakes Impacts:

Remarks: Native populations are considered extinct in Montana (Holton 1990) except for a remnant population in the Big Hole River (Wydoski and Whitney 2003).  The species has be re-stocked in the Red Rock, Madison, Gallatin and Sun drainages, as well as other locations. A relict population was present in the Great Lakes up until the 1930s, when it was extirpated due to competition with other introduced salmonids, habitat degradation, and fishing pressure (Hubbs and Lagler 1958). The Upper Missouri River population has been proposed to be classified as threatened or endangered under the Endangered Species Act (USFWS 2010).

References (click for full reference list)

Other Resources:
USGS/NAS Technical Species Profile

Author: Pam Fuller, Matt Cannister, and Matt Neilson

Contributing Agencies:

Revision Date: 8/28/2019

Peer Review Date: 11/5/2012

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.