Thaleichthys pacificus (Richardson, 1836)
Eulachon
photo by Bull. U.S. Bur. Fish.

Family:  Osmeridae (Smelts)
Max. size:  34 cm TL (male/unsexed); max. reported age: 5 years
Environment:  pelagic-neritic; freshwater; brackish; marine; depth range 0 - 300 m, anadromous
Distribution:  North Pacific: west of Saint Matthew Island and Kuskokwim Bay in the Bering Sea, and Bowers Bank in the Aleutian Islands to Monterey Bay, California, USA. Populations from northern British Columbia are separate from those in the Fraser River (Ref. 10276).
Diagnosis:  Dorsal spines (total): 0-0; Dorsal soft rays (total): 10-13; Anal spines: 0-0; Anal soft rays: 18-23; Vertebrae: 65-72. Distinguished by the large canine teeth on the vomer and 18 to 23 rays in the anal fin (Ref. 27547). Adipose fin sickle-shaped; paired fins longer in males than in females; all fins with well developed breeding tubercles in ripe males which are poorly developed or absent in females (Ref. 27547). Adult coloration is brown to blue on back and top of the head, the sides lighter to silvery white, and the ventral surface white; speckling is fine, sparse and restricted to the back; peritoneum is light with black speckles (Ref. 6885). Fins transparent, pectorals and caudal often dusky (Ref. 27547). During spawning, male fish has a distinctly raised ridge along the middle of the body and a rough texture, differentiating it from the female which is smaller, smoother and shinier.
Biology:  Found near shore and in coastal inlets and rivers (Ref. 2850). Possibly to 625 m depth (Ref. 6793). Spends most of its life in the sea, returning to freshwater streams to spawn (Ref. 27547). There is evidence of return to natal streams (Ref. 10276). May migrate up to 160 km upstream. Feeds on plankton and only while at sea (11699, 10276). Excellent food fish and source of oil (15% body wt.). Anadromous (Ref. 96339).
IUCN Red List Status: Least Concern (LC); Date assessed: 01 March 2012 Ref. (126983)
Threat to humans:  harmless


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