St. Lawrence species

Rainbow smelt

Osmerus mordax

Type of resource

  • Fish
  • Pelagic fish

Culinary name


Status of the resource

  • Vulnérable

In season

Fresh at the end of winter and the beginning of spring.

SIZE : 20 to 25 cm with a maximum of 35.6 cm.

LIFE EXPECTANCY : Up to 7 years.

LIFE CYCLE : In spring, rainbow smelt migrate to freshwater to spawn. During the nights between April and June, the female can lay up to 80,000 eggs. These stick to the bottom thanks to their adhesive envelope. Once born, the rainbow smelt move to salt water to grow. They will return to freshwater for the next spawning season.

Credit : Claude Nozères, photo takin in 2010.

Rainbow smelt has a silvery color with rainbow highlights on its sides, a white belly, and a darker back in shades of green. Its fins are somewhat large and transparent. It has an elongated body with large scales. Its wide mouth extends under the eyes, and it has big and well-developed sharp-edged teeth.

In the water column, usually 150 m deep, but which can reach 450 m in waters with variable salinity.

Anadromous fish, rainbow smelt are found at the mouths of rivers in winter.


Marine worms





  • In autumn, gillnet for commercial fishing.
  • For recreational fishing (main type of fishing): angling on ice in winter (pêche blanche).
  • Dip-net fishing in sprin.
  • Fixed-line fishing, hand-fishing, or harpoon fishing from wharves during the summer.


  • Sports fishing permits required
  • Quotas from 60 to 120, depending on the fishing zone

Seven distinct populations of rainbow smelt are found in the waters of the St. Lawrence Seaway.  The rainbow smelt found in the southern estuary is classified as being vulnerable.

Source of protein and fatty acid.

Lean white flesh with a finely flaky, soft texture. Its tender bones are also edible.

Rainbow smelt is often eaten whole, pan-fried, or deep-fried if it is small. Larger rainbow smelt can also be served whole, en papillote, oven-baked, or served as a fillet.


  • Due to its vulnerable status, we do not recommend eating rainbow smelt.

Sweeter during winter

To withstand the cold waters of winter, rainbow smelt accumulate glycerol and an anti-freeze protein in their tissues. These components give the rainbow smelt a sweeter taste than in summer.