FWS Focus

Overview

Characteristics
Overview

The Arctic grayling is also considered to be a salmonoid, or a member of the salmon family. They are the only salmonoid with a distinguishing sail-like dorsal and the only grayling species found in North America. 

These fish inhabit open water in clear, cold, medium to large rivers and lakes. Adult Arctic grayling spawn in mountain streams in shallow water with a rock and gravel bottom and have a strong current 

Fluvial, or river dwelling, Arctic grayling are still present in southwestern Montana. Unfortunately, there has been a signi?cant decline in the range and abundance of fluvial grayling which were once widespread in the Upper Missouri River Basin above Great Falls, Montana. Currently there are only two fluvial grayling populations in Montana.

Scientific Name

Thymallus arcticus
Common Name
Arctic grayling
FWS Category
Fishes
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Physical Characteristics

Characteristics
Physical Characteristics

Migration Behavior 

The Arctic grayling is a migratory fish. During the winter, these fish are found in the deep pools of river systems where the water never freezes during the winter. In late spring to early summer these fish will migrate upstream to their traditional spawning areas. Arctic grayling in Montana have been recorded swimming 60 miles in between habitats in the Big Hole River, Montana. 

Weight

The heaviest published weight for Arctic grayling was 8.4 pounds.

Size & Shape

Common length for Arctic grayling is 13.5 inches with the longest reported specimen being 30 inches.

Characteristic category

Habitat

Characteristics
Habitat

Arctic grayling inhabit open water in clear, cold, medium to large rivers and lakes. Adult Arctic grayling spawn in mountain streams in shallow water with a rock and gravel bottom and have a strong current.

Lake
River or Stream
Characteristic category

Food

Characteristics
Food

Young grayling feed on zooplankton, with a gradual shift to immature insects as they grow older. Adult grayling feed on surface insects but also on ?sh, ?sh eggs, lemmings and planktonic crustaceans.

Characteristic category

Life Cycle

Characteristics
Reproduction

Arctic grayling begin to spawn between the ages of 3 and 4 years. In the spring, adult Arctic grayling move into tributaries and male Arctic grayling begin to establish territories before the females arrive. Adult grayling then begin to school and will eventually begin to reproduce by broadcast spawning. 

In early fall, Arctic grayling will begin to slowly migrate back to overwintering areas that are normally downstream of their feeding areas. 

Characteristic category

Behavior

Characteristics
Behavior

Migration Behavior 

The Arctic grayling is a migratory fish. During the winter, these fish are found in the deep pools of river systems where the water never freezes during the colder months. In late spring to early summer, these fish will migrate upstream to their traditional spawning areas. Arctic grayling in Montana have been recorded swimming 60 miles in between habitats in the Big Hole River, Montana. 

Geography

Characteristics
Range

Arctic grayling are native to drainages of the Arctic Ocean, Hudson Bay, Upper Mississippi and Northern Paci?c Ocean in North America. Two distinct populations historically inhabited waters in Michigan and Montana. The distinct population of Arctic grayling in Michigan is now extinct although reintroduction efforts are ongoing. Fluvial, or river dwelling, Arctic grayling are still present in southwestern Montana. Unfortunately, there has been a signi?cant decline in the range and abundance of fluvial grayling which were once widespread in the Upper Missouri River Basin above Great Falls, Montana. Currently there are only two fluvial grayling populations in Montana, in the Big Hole River, upstream from Divide, Montana and the Upper Ruby River near Alder, Montana.  

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