Arctic Charr (Salvelinus alpinus)

Arctic Charr (Salvelinus alpinus)

The arctic charr is one of five species that are actually classified as charr. It varies so greatly in coloration that many specimens are thought to be species or subspecies, resulting in a great deal of confusion and a tremendous problem for taxonomists.

This confusion extended to anadromous and nonanadromous forms, the latter including three New England charr—the blueback trout, the Sunapee trout, and the Quebec red trout, which were once separately recognized species but which were all reclassified and folded under the highly inclusive umbrella S. alpinus in 1974.

The arctic charr exists in anadromous (migrating annually to the sea) and nonanadromous (landlocked or living entirely in freshwater) forms. Because of plentiful food resources in the ocean, the anadromous version tends to be larger than the landlocked one and of more importance. The landlocked charr is blocked from the sea by some physical barrier. It is found everywhere that the sea-run charr exists but also occurs in smaller numbers much farther to the south.


Identification

Like all members of the Salvelinus genus, the arctic charr has light-colored spots on its body, including below the lateral line, and the leading edges of all fins on the lower part of the body are milk white. It is a long and slender fish with a small, pointed head; an adipose fin; an axillary process at the base of each pelvic fin; and a slightly forked tail that almost appears squared. It also has very fine scales, so deeply embedded that the skin has a smooth, slippery feel. Unlike the trout, it has teeth only in the central forward part of its mouth.

Coloration is highly variable among seagoing and landlocked forms and can change even within individual stocks. In a general sense, the arctic charr is silvery in nonspawning individuals, with deep green or blue shading on the back and upper sides and a white belly.

Spawning males exhibit brilliant red or reddish-orange coloration on the sides, the underparts, and the lower fins; their backs are muted, sometimes without the blue or green coloration or possibly with orange to olive hues. A spawning male of some populations will develop a kype, and some have humped backs. Spawning females are also colorful, although the red is less intense and present only on their flanks and bellies; their backs remain bluish or greenish.

Size

Arctic charr may live up to 30 years and grow to 3 feet in length. Sea-run charr grow much larger, and the all-tackle world record is a 32-pound, 9-ounce sea-run fish that was caught in 1981 in the Tree River of Canada’s Northwest Territories. In most places, sea-run arctic charr range up to 10 pounds and average 7 pounds; landlocked fish normally weigh a few pounds. A sea-run arctic charr weighing more than 15 pounds is a trophy in most waters.

Life history/Behavior

The charr spawns in September or October in colder regions and later if it lives farther south; a water temperature of around 39°F is preferred. The spawning female seeks out a suitable bed of gravel or broken rock. The anadromous charr lives in its birth river for at least 4 years before migrating to the sea for the first time. It will return anywhere between mid-August and late September, before the ice begins to form again. The larger fish return first.

Unlike other salmonids, all arctic charr leave the sea and overwinter in rivers and lakes, although not all are spawners; some go back and forth several times before they first spawn. Nonanadromous or landlocked charr tend to reach maturity when they are smaller and younger. They have the same lifestyle as their anadromous brethren.

Food

Insects, mollusks, and small fish constitute the diet of arctic charr. Ninespine sticklebacks are important forage in some places. The charr often does not eat in the winter, when its metabolic rate slows in tune with a cooling environment. Rather, it lives on the fat it has accumulated during the summer, and growth is accordingly limited during the cold months and greatest when at sea.

Other Names

Seagoing fish
char, red charr; Cree: awanans; Danish: fjeldørred; French: omble chevalier; German: saibling; Greenlandic: eqaluk; Icelandic: bleikja; Inuit: iqalugaq, iqaluk, ilkalupik, ivisaaruq, kisuajuq, majuqtuq, nutiliarjuk, situajuq, situliqtuq, tisuajuq; Japanese: iwana; Norwegian: arktisk roye, royr; Russian: goletz; Swedish: röding.

Landlocked fish
blueback charr, blueback trout, Sunapee trout, golden trout (Sunapee), Quebec red.

Distribution

The most northerly ranging fish, the arctic charr is circumpolar in distribution, occurring in pure and cold rivers and lakes around the globe, from the northeastern United States north and west across northern Canada, Alaska, and the Aleutian Islands, and from northern Russia south to Lake Baikal and Kamchatka, as well as in Iceland, Great Britain, Scandinavia, the Alps, and Spitsbergen, among other places.

In North America, they occur from Alaska around the Bering Sea and along the Arctic coast to Baffin Island, along the coastline of Hudson Bay, and from the northern Quebec coast easterly and southerly to Maine and New Hampshire. Except in larger rivers, they seldom range far inland here, although there are a few pockets of landlocked charr.

In the Northwest Territories and Nunavut Territory, where they are especially known, charr distribution includes most coastal rivers, some coastal lakes, the streams of the high-arctic islands, and several islands in Hudson Bay.

Habitat

In their ocean life, arctic charr remain in inshore waters; most do not migrate far. In rivers, they locate in pools and runs. The lakes inhabited by anadromous and landlocked charr are cold year-round, so the fish remain near the surface or in the upper levels and may gather at the mouths of tributaries when food is plentiful.
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