Pacific salmonid life cycle

Eggs and alevin

Under the gravel, embryos develop within the eggs. They hatch as alevin, with an attached yolk sac for food.

Illustration: Eggs and alevin

Fry

In the stream, fry emerge from the gravel and swim in search of tiny aquatic insects and other food.

Illustration: Coho fry

Smolts

Migrating to estuaries, silvery smolts begin their adaptation to salt water.

Illustration: Chinook smolts

Adults

In the ocean, adults travel thousands of miles, feeding and growing before returning to their stream of origin.

Illustrations: Steelhead trout, Chum salmon, Coho salmon, Chinook salmon, Sockeye salmon, Pink salmon

Migration

Swimming upstream, salmonids fight past rapids and waterfalls. Spawning colours appear; males develop hooked jaws, sharp canine teeth and in some species humped backs.

Illustrations: Chinook migrating, Sockeye males fighting

Spawners

In gravel nests, females lay thousands of eggs that are fertilized with milt from males. Their life cycle complete, salmonids die soon after spawning.

Illustrations: Sockeye pair spawning, Chum female digging redd