The Eulachon (Thaleichthys pacificus) also known as Hooligan, Ooligan, or Candlefish, is a small fish found in marine waters along thePacific coast of North America from northern California to Alaska. Most of their adult life is spent in the ocean, but they do return to their natal freshwater streams and rivers to spawn and die.

Its common names can be quite confusing. The name “Candlefish” derives from the fact that when they spawn, their body weight is 15% fat and when the fish is caught, dried, and strung on a wick, it could be burned as a candle. This name was most often used by early explorers. The name Eulachon comes from the Chinookan language. “Hooligan” and “ooligan” have possibly been derived from the common name Eulachon.

The Eulachon were an important part of the diet of the people in the regions where they occurred,and they were valuable in trade as well. The species was caught using traps, rakes, and nets. The harvest continues today, with other residents taking part in the exploitation of the large runs. Today harvested eulachon are typically stored frozen and thawed as needed. They may also be dried, smoked, or canned. Eulachon were also processed for their rich oil.

The Eulachon feeds primarily on plankton as well as fish eggs, insect larvae, and small crustaceans. It forms an important part of the diet of many ocean and shore predators, and serves as a prominent food source for people living near its spawning streams.