Trout Life Cycle

 The egg stage lasts for about 21 to 28 days in optimal conditions such as an artificial hatchery.  Eggs that arrive at the small fry hatchery are about 14 to 21 days old. They hatch in approximately seven more days.

The sac fry or alevin (larval) stage lasts about seven to ten days.  During this period the yolk sac is gradually absorbed by the fry. It provides all the nutrients necessary to sustain fry growth. 

Buttoning-up occurs when alevin absorb the yolk sac and begin to feed on zooplankton. Fry swim close to the water surface, allowing the swim bladder to fill with air and help the fry float through water.

When a fry grows to 2-5 inches, it becomes a fingerling. When it develops large dark markings, it then becomes a parr. We will release the Rainbow Trout into the Chattahoochee River at this stage. 

In the natural habitat, a trout avoids predators, including wading birds and larger fish, by hiding in underwater roots and brush. As a juvenile, a trout resembles an adult but is not yet old or large enough to spawn.

Now the trout are adults. A trout’s life span is typically about 5 years. Trout turn vibrant in color during spawning and then lay eggs in fish nests, or redds, in the gravel. The life cycle of the Rainbow Trout continues into the egg stage again.