Trout Life Cycle

Trout can live for about seven years. Most trout are born, grow up, lay eggs and die in lakes or streams. Some trout, though, become very large migratory fish and travel more in their seven years than some people do in a lifetime. In this way, they are similar to their salmon relatives. In fact, they may migrate from their lake or stream to the ocean and back three or four times.

spawn through hatch
At two years old, trout are ready to reproduce. Their colors change by getting brighter, and they find mates. Some species mate in the fall, and other species mate in the spring. A female trout lays her eggs which are fertilized by a male in a redd, or nest, built in the gravels of a freshwater lake or stream. Baby trout hatch before they’re ready to swim. These tiny trout, called alevins, live on the yolk from their egg sacs.

hatch through adult
Young trout, called fry, use up the food in their egg sacs and swim around in the lake or stream where they were born. They now have to find their own food – mostly tiny organisms called zooplankton. Over the next few years, fry grow up, eating mostly insects and worms. They get the spots, stripes and brilliant colors of an adult trout.