Species and Habitat Outlines

Eulachon
TAXONOMY

Phylum: Chordata
Class: Osteichthyes
Order: Salmoniformes
Family: Osmeridae

 

ECOLOGICAL DATA

Distribution: common along B.C. coast; particularly abundant in spring in large rivers and larger streams.

Habitat: mature adults ascend larger rivers (e.g. Fraser and Nass) during mid-March to mid May to spawn; eggs are laid in coarse sand or gravel in freshwater; most adults die after spawning; eggs adhere to sand and hatch in 2-3 weeks; larvae (4-5 mm long) are carried by currents to sea; may rear in estuaries; widely dispersed by currents; juveniles use deeper water as they grow; juveniles and adults feed at moderate depths in offshore waters (and have been a significant bycatch in offshore shrimp trawl fisheries).

Tidal elevation: adults use shallow water (i.e. less than 20 m) during spring spawning migration; larvae and juveniles may use shallow estuarine habitats for rearing.

Food: larvae and post-larvae eat phytoplankton, copepod eggs, copepods, mysids, barnacle larvae; juveniles prey on copepods; larger juveniles feed on euphausiids, copepods and other crustaceans.

Predators: important prey for white sturgeon, dogfish, salmon, Pacific halibut, Pacific cod, gulls and sea birds, marine mammals.

GROWTH RATE

Young-of-the-year range from 18-71 mm, 71-95 mm at 1 yr and 165 mm at 5 yr.; sexually mature at 2 yr (72-111 mm).

FISHERY

Small commercial and Native fisheries in Fraser River; 1986 commercial catch was 50 t valued at $49,000; north coast closed for Native harvest.

REFERENCES

Barraclough, W.E. 1964. Contribution to the marine life history of the eulachon Thaleichthys pacificus. J. Fish. Res. Board Can. 21: 1333-1337.

Hart, J.L. 1973. Pacific fishes of Canada. Fish. Res. Board Can. Bull. 180: 83-84.

Hart, J.L., and J.L. McHugh. 1944. The smelts (Osmeridae) of British Columbia. Fish. Res. Board Can. Bull. 64: 27 p.

Northcote, T.G. 1974. Biology of the lower Fraser River: a review. Univ. B.C. Westwater Res. Cen. Tech. Rep. 3: 94 p.

Scott, W.B., and E.J. Crossman. 1973. Freshwater fishes of Canada. Fish. Res. Board Can. Bull. 184: 320-325.

 

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