Arctic grayling

General information about Arctic grayling (Thymallus arcticus), a cold-water fish species in Alberta.

Description

Size

  • Average body length ranges from 30 to 40 centimetres (12 to 16 inches), and can measure up to 55 centimetres (22 inches).
  • Average weight ranges from 300 to 800 grams (0.6 to 1.8 pounds), and can measure up to 1.3 kilograms (2.9 pounds)

Appearance

  • Arctic grayling can be identified by their colourful and very large dorsal fin, which is much larger than that of any other cold-water fish. The top of the dorsal fin is rounded.
  • Grayling can also be recognized by their large scales with brown or black spots on the body behind the head.
  • Grayling can also be recognized by their large scales with brown or black spots on the body behind the head.

Distribution

  • Arctic grayling are native to North America, and are found primarily in the Athabasca, Hay and Peace river drainage systems of Alberta.
  • A small population of this fish can be found in the Belly River in southwestern Alberta.
  • A small number of mountain ponds have been stocked with grayling.

Natural History

Habitat

  • Arctic grayling are typically found in streams and rivers.

Food

  • The diet of Arctic grayling consists of a wide range of both aquatic and terrestrial invertebrates.
  • Fish eggs and small fish may also supplement the diet.

Reproduction and Growth

Breeding Behaviour

  • Spawning occurs from May to June.
  • Grayling migrate from lakes and larger rivers to smaller streams to spawn.
  • The males on the spawning ground are territorial and will drive away other males when confronted.
  • Actual spawning occurs during daylight. Eggs and milt (a milky excretion of male sperm cells) are deposited.
  • Intense quivering by both the male and female during spawning displaces some of the bottom material of the spawning ground and buries some of the fertilized eggs. No actual nest is built.
  • After spawning, Arctic grayling return to the lakes and larger rivers.
  • The eggs hatch quickly, 13 to 18 days after being deposited.

Conservation and Management

Status

Arctic grayling are classified as Sensitive in the current General Status of Alberta Wild Species report. See:

Alberta's Endangered Species Conservation Committee (ESCC) has identified Arctic grayling as a Species of Special Concern — a species that without human intervention may soon become threatened with extinction. See information on the Endangered Species Conservation Committee and Species of Special Concern at:

Issues

Populations of this fish have decreased over the past few decades due to:

  • Increased accessibility by humans to remaining habitat, resulting in increased harvest
  • Blocked migration routes and altered stream flow resulting from improperly placed culverts in newly constructed roads

Current management

Fish Sustainability Index

Alberta's Arctic grayling populations have been assessed under the Fish Sustainability Index, see:

Fishing

Arctic grayling are cold-water game fish subject to current Alberta sportfishing regulations. For details, see the My Wild Alberta website at: