The Arctic grayling (''Thymallus arcticus'') is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

freshwater fish Freshwater fish are fish species that spend some or all of their lives in bodies of fresh water such as rivers, lakes, ponds and inland wetlands, where the salinity is less than 1.05%. These environments differ from marine habitats in many wa ...

in the

salmon Salmon (; : salmon) are any of several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the genera ''Salmo'' and ''Oncorhynchus'' of the family (biology), family Salmonidae, native ...

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Salmonidae Salmonidae (, ) is a family (biology), family of ray-finned fish, the only extant member of the suborder Salmonoidei, consisting of 11 extant genera and over 200 species collectively known as "salmonids" or "salmonoids". The family includes salmo ...

. ''T. arcticus'' is widespread throughout the

Arctic The Arctic (; . ) is the polar regions of Earth, polar region of Earth that surrounds the North Pole, lying within the Arctic Circle. The Arctic region, from the IERS Reference Meridian travelling east, consists of parts of northern Norway ( ...

and

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the cont ...

drainages in

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

, and

Siberia Siberia ( ; , ) is an extensive geographical region comprising all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has formed a part of the sovereign territory of Russia and its predecessor states ...

, as well as the upper

Missouri River The Missouri River is a river in the Central United States, Central and Mountain states, Mountain West regions of the United States. The nation's longest, it rises in the eastern Centennial Mountains of the Bitterroot Range of the Rocky Moun ...

drainage in

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

. In the U.S. state of

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

, an introduced population is found in the

Lee Valley The Lea Valley (also spelt Lee Valley), the valley of the River Lea, has been used as a transport corridor, a source of sand and gravel, an industrial area, a water supply for London, and a recreational area. The London 2012 Summer Olympics wer ...

and other lakes in the White Mountains. They were also stocked at Toppings Lake by the

Teton Range The Teton Range is a mountain range of the Rocky Mountains in North America. It extends for approximately in a north–south direction through the U.S. state of Wyoming, east of the Idaho state line. It is south of Yellowstone National Park, ...

and in lakes in the high

Uinta Mountains The Uinta Mountains ( ) are an east-west trending mountain range in northeastern Utah extending a short distance into northwest Colorado and slightly into southwestern Wyoming in the United States. As a subrange of the Rocky Mountains, they are u ...

in Utah, as well as alpine lakes of the

Boulder Mountains (Idaho) The Boulder Mountains are part of the Rocky Mountains in the western United States. Located in central Idaho, they stretch from a few miles north of Ketchum to north to near Challis, and part of the range is within the Sawtooth National Recre ...

central Idaho Central Idaho is a geographical term for the region located northeast of Boise and southeast of Lewiston in the U.S. state of Idaho. It is dominated by federal lands administered by the United States Forest Service and the Bureau of Land Managem ...

Taxonomy

The scientific name of the Arctic grayling is ''Thymallus arcticus''. It was named in 1776 by German zoologist

Peter Simon Pallas Peter Simon Pallas Fellow of the Royal Society, FRS FRSE (22 September 1741 – 8 September 1811) was a Prussia, Prussian zoologist, botanist, Ethnography, ethnographer, Exploration, explorer, Geography, geographer, Geology, geologist, Natura ...

from specimens collected in Russia. The name of the genus ''Thymallus'' first given to grayling (''T. thymallus'') described in the 1758 edition of ''Systema Naturae'' by Swedish zoologist

Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

originates from the faint smell of the herb

thyme Thyme () is a culinary herb consisting of the dried aerial parts of some members of the genus ''Thymus (plant), Thymus'' of flowering plants in the mint family Lamiaceae. Thymes are native to Eurasia and north Africa. Thymes have culinary, medici ...

, which emanates from the flesh.

Description

Arctic grayling grow to a maximum recorded length of and a maximum recorded weight of . Of typical thymalline appearance, the Arctic grayling is distinguished from the similar

European grayling ''Thymallus thymallus'', the grayling or European grayling, is a species of freshwater fish in the salmon family Salmonidae. It is the only species of the genus ''Thymallus'' (the graylings) native to Europe, where it is widespread from the Unite ...

(''T. thymallus'') by the absence of

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage The fus ...

and

anal Anal may refer to: Related to the anus *Related to the anus of animals: ** Anal fin, in fish anatomy ** Anal vein, in insect anatomy ** Anal scale, in reptile anatomy *Related to the human anus: ** Anal sex, a type of sexual activity involving ...

spines and by the presence of a larger number of soft rays in these fins. There is a dark midlateral band between the pectoral and pelvic fins, and the flanks may possess a pink

iridescence Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear gradually to change colour as the angle of view or the angle of illumination changes. Iridescence is caused by wave interference of light in microstru ...

. ''T. a. arcticus'' has been recorded as reaching an age of 18 years.

Range

Arctic grayling are widespread in Arctic Ocean drainages from

Hudson Bay Hudson Bay, sometimes called Hudson's Bay (usually historically), is a large body of Saline water, saltwater in northeastern Canada with a surface area of . It is located north of Ontario, west of Quebec, northeast of Manitoba, and southeast o ...

, Canada to

and in Arctic and Pacific drainages to central

Alberta Alberta is a Provinces and territories of Canada, province in Canada. It is a part of Western Canada and is one of the three Canadian Prairies, prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, t ...

and

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

in Canada. They do not occur naturally in the

Fraser Fraser may refer to: Places Antarctica * Fraser Point, South Orkney Islands Australia * Fraser, Australian Capital Territory, a suburb in the Canberra district of Belconnen * Division of Fraser (Australian Capital Territory), a former federal ...

and Columbia river basins. There are remnant native populations of fluvial Arctic grayling in the upper

drainage in the

Big Hole River The Big Hole River is a tributary of the Jefferson River, approximately 153 miles (246 km) long, in Beaverhead County, Montana, Beaverhead County, in southwestern Montana, United States. It is the last habitat in the contiguou ...

and Red Rock basin (" Montana Arctic grayling"). Fluvial Arctic grayling have been reestablished in the upper

Ruby River The Ruby River is a tributary of the Beaverhead River, approximately 76 mi (122 km) long, in southwestern Montana in the United States. It rises in the Beaverhead National Forest in southwestern Madison County, Montana, Madison County ...

, a tributary of the

Beaverhead River The Beaverhead River is an approximately tributary of the Jefferson River in southwest Montana (east of the Continental Divide). It drains an area of roughly . The river's original headwaters, formed by the confluence of the Red Rock River and ...

. The native range formerly extended south into the

Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes spanning the Canada–United States border. The five lakes are Lake Superior, Superior, Lake Michigan, Michigan, Lake Huron, H ...

basin in

Michigan Michigan ( ) is a peninsular U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, Upper Midwestern United States. It shares water and land boundaries with Minnesota to the northwest, Wisconsin to the west, ...

, where the species was extirpated by 1936 due to habitat destruction, unregulated logging, and competition from non-native fish species. The arctic grayling occurs naturally in the Arctic Ocean basin in Siberia from the Ob to

Yenisei The Yenisey or Yenisei ( ; , ) is the fifth-longest river system in the world, and the largest to drain into the Arctic Ocean. Rising in Mungaragiyn-gol in Mongolia, it follows a northerly course through Lake Baikal and the Krasnoyarsk Dam b ...

drainages and in

European Russia European Russia is the western and most populated part of the Russia, Russian Federation. It is geographically situated in Europe, as opposed to the country's sparsely populated and vastly larger eastern part, Siberia, which is situated in Asia ...

in some tributaries of

Pechora river The Pechora (; Komi: Печӧра; Nenets: Санэроˮ яха) is the sixth-longest river in Europe. Flowing from Northwest Russia and into the Arctic Ocean, it lies mostly in the Komi Republic but the northernmost part crosses the Nenets A ...

. Lake dwelling forms of Arctic grayling have been introduced in suitable lake habitats throughout the

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...

including lakes in the

in Wyoming,

and the high

in Utah,

Cascade Mountains The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as many of those in the ...

and

Sierra Nevada Mountains The Sierra Nevada ( ) is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

as far south as

Life cycle

Several life history forms of Arctic grayling occur:

fluvial A river is a natural stream of fresh water that flows on land or inside caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it ru ...

populations that live and spawn in rivers;

lacustrine A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from t ...

populations that live and spawn in lakes; and

potamodromous Fish migration is animal migration, mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few ...

populations that live in lakes and spawn in tributary streams. The Arctic grayling occurs primarily in cold waters of mid-sized to large rivers and lakes, returning to rocky streams to breed. The various subspecies are omnivorous.

Crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s and insect

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e, and fish eggs form the most important food items. Larger specimens of ''T. arcticus'' become

piscivorous A piscivore () is a carnivorous animal that primarily eats fish. Fish were the diet of early tetrapod evolution (via water-bound amphibians during the Devonian period); insectivory came next; then in time, the more terrestrially adapted rept ...

and the immature fish feed on

zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

and insect larvae. ArcticGraylingUSFWS

Spawning takes place in the spring. Adult fish seek shallow areas of rivers with fine, sand substrate and moderate current. Males are territorial and court females by flashing their colourful dorsal fins; the fins are also used to brace receptive females during the vibratory release of

milt Milt is the seminal fluid of fish, mollusks, and certain other water-dwelling animals. They reproduce by spraying this fluid which contains the sperm, onto roe (fish eggs). It can also refer to the sperm sacs or testes that contain the semen. ...

and

roe Roe, ( ) or hard roe, is the fully ripe internal egg masses in the ovaries, or the released external egg masses, of fish and certain marine animals such as shrimp, scallop, sea urchins and squid. As a seafood, roe is used both as a cooking, c ...

. The fish are nonguarders: the eggs are left to mix with the substrate. Although the Arctic grayling does not excavate a nest, the highly energetic courtship and mating tends to kick up fine material which covers the

zygote A zygote (; , ) is a eukaryote, eukaryotic cell (biology), cell formed by a fertilization event between two gametes. The zygote's genome is a combination of the DNA in each gamete, and contains all of the genetic information of a new individ ...

s. The zygote is small (approximately in diameter) and the embryo will hatch after two to three weeks. The newly hatched embryo remains in the substrate until all the

yolk Among animals which produce eggs, the yolk (; also known as the vitellus) is the nutrient-bearing portion of the egg whose primary function is to supply food for the development of the embryo. Some types of egg contain no yolk, for example bec ...

has been absorbed. They emerge at a length of around , at which time they form

shoals In oceanography, geomorphology, and geoscience, a shoal is a natural submerged ridge, bank, or bar that consists of, or is covered by, sand or other unconsolidated material, and rises from the bed of a body of water close to the surface or ...

at the river margins. The juveniles grow quickly during their first two years of life.

Conservation

Arctic grayling are considered a secure species throughout their range. Although some populations at the southern extent of its native range have been extirpated, it remains widespread elsewhere and is not listed on the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is an inventory of the global conservation status and extinction risk of biological ...

of threatened species. The fluvial population in the upper Missouri river basin once merited a high priority for listing under the

Endangered Species Act The Endangered Species Act of 1973 (ESA; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting and conserving imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of e ...

(ESA) by the

US Fish & Wildlife Service The United States Fish and Wildlife Service (USFWS or FWS) is a U.S. federal government agency within the United States Department of the Interior which oversees the management of fish, wildlife, and natural habitats in the United States. Th ...

(FWS). This unique southernmost population is now extirpated from all areas of the basin with the exception of the

watershed. In preparation for an ESA listing, the US FWS began implementing a "Candidate Conservation Agreement with Assurances" (CCAA). This agreement protects cooperating landowners from being prosecuted under the ESA "takings" clause so long as they fulfill specific obligations, spelled out in a contractual arrangement and intended to restore the dwindling population. Finally, in 2014 the FWS determined not to list the grayling under ESA, due to the effectiveness of the CCAA. In 2025, efforts to reintroduce Arctic grayling to

streams began, with 400,000 eggs planted in coldwater streams as part of a collaborative restoration initiative. The Arctic grayling is economically important; it is a "key subsistence species" for the

Iñupiat The Inupiat (singular: Iñupiaq), also known as Alaskan Inuit, are a group of Alaska Natives whose traditional territory roughly spans northeast from Norton Sound on the Bering Sea to the northernmost part of the Canada–United States borde ...

people of the

Alaska North Slope The Alaska North Slope is the region of the U.S. state of Alaska located on the northern slope of the Brooks Range along the coast of two marginal seas of the Arctic Ocean, the Chukchi Sea being on the western side of Point Barrow, and the Beau ...

, it is raised commercially for

food Food is any substance consumed by an organism for Nutrient, nutritional support. Food is usually of plant, animal, or Fungus, fungal origin and contains essential nutrients such as carbohydrates, fats, protein (nutrient), proteins, vitamins, ...

and it is one of the most important species for

sport fishing Recreational fishing, also called sport fishing or game fishing, is fishing for leisure, exercise or competition. It can be contrasted with commercial fishing, which is occupational fishing activities done for profit; or subsistence fishing, ...

in Alaska.

Notes

;Citations ;Sources * *FWS (2004). U.S. Fish and Wildlife Service Species Assessment and Listing Priority Assignment Form for fluvial Arctic grayling (

distinct population segment {{no footnotes, date=February 2018 A distinct population segment (DPS) is the smallest division of a taxonomic species permitted to be protected under the U.S. Endangered Species Act. ''Species'', as defined in the Act for listing purposes, is a ...

of the Upper Missouri River), commonly called Montana Arctic grayling. November 30, 2004.

External links

EcoRover blog about Big Hole River graylingPat Munday's rating of Big Hole Watershed Committee effectiveness in Big Hole River grayling restorationLength and age at maturity of Arctic grayling in the Snake River during 2003 / by Alfred L. DeCicco and Andrew D. Gryska.
Hosted b
Alaska State Publications Program

Summer abundance of Arctic grayling in the Chena River, 2005 by Klaus G Wuttig; Steven M Stroka; Alaska. Division of Sport Fish.; Alaska. Division of Commercial Fisheries.
Hosted b
Alaska State Publications Program
{{Authority control

Arctic grayling The Arctic grayling (''Thymallus arcticus'') is a species of freshwater fish in the salmon family Salmonidae. ''T. arcticus'' is widespread throughout the Arctic and Pacific drainages in Canada, Alaska, and Siberia, as well as the upper Missou ...

Freshwater fish of the Arctic Freshwater fish of Asia Freshwater fish of the United States Fish of Canada Fish of Russia Fish of the Western United States Fauna of the Rocky Mountains

Taxa named by Peter Simon Pallas