E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

Theragra chalcogramma (Pallas, 1814)
Alaska Pollock; Walleye Polloch; Walleye Polloch
Family: Gadidae

Source: Distribution of Theragra chalcogramma as compiled by Aquamaps

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Species Information

Dorsal spines (total): 0; Dorsal soft rays (total): 38 - 48; Anal spines: 0; Anal soft rays: 33 - 42. The dorsal fins are widely separated. The pelvic fins have a slightly elongated filament. The lateral line is continuous to about the back end of the first dorsal-fin base; it is interrupted at the read of the body. On the head are lateral line pores. Body color is olive green to brown on the back and becomes silvery on the sides and pale ventrally, often with mottled patterns or blotches.

Source: FishBase. Cohen, D.M., T. Inada, T. Iwamoto and N Scialabba. 1990 . (Ref. 1371)

Biology

Species Biology

The adults usually live near to the sea floor, but sometimes they also appear near the surface (Ref. 1371). They perform diurnal vertical migrations (Ref. 1371). They mainly feed on krill (Ref. 39882) but they also eat fishes and crustaceans (Ref. 6885). The adults which are spawning are often solely captured for their roe. Environment: benthopelagic; non-migratory; brackish; marine; depth range 0 - 1280 m (Ref. 50550). Climate: polar; 68°N - 34°N, 129°E - 120°W

Source: FishBase. Cohen, D.M., T. Inada, T. Iwamoto and N Scialabba. 1990 . (Ref. 1371)

Distribution

North Pacific: from Kivalina, Alaska, to the southern Sea of Japan and to Carmel, California, USA. The occurrence off the northern part of Baja California (Mexico), as reported from Quast and Hall, (1972) (Ref. 6876) is apparently erroneous.

Source: FishBase. Cohen, D.M., T. Inada, T. Iwamoto and N Scialabba. 1990 . (Ref. 1371)

Status Information

Origin Status	Provincial Status	BC List (Red Blue List)	COSEWIC
Native	SNR	No Status	Not Listed

BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

Taxonomic and Nomenclatural Links

Genetic and lineage information (NCBI Taxonomy Browser)

Additional Range and Status Information Links

NatureServe Explorer
University of Alaska Museum

Additional Photo Sources

Flickr Image Search
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Images from Calphoto

Related Databases

fishbase

General References

FishBase References
Google Scholar Search

Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC: Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 2025-06-23 12:21:23 PM]

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