Trout Life Cycle. Egg. The egg is the first step in the life cycle of the trout. Just after fertilization eggs are very soft and sticky. They are called ‘ green ’ eggs. The source of energy for the embryo comes from the yolk. The developing embryo uses the yolk as its food. Eyed-Egg.
The egg is the first step in the life cycle of the trout.
They are called ‘green’ eggs.
The developing embryo uses the yolk as its food.
When the egg is in this stage it is more stable. The outer surface is harder than when the egg was first laid.
The egg is called an eyed -egg because the black dots you see are the eyes of the embryo inside.
When the trout hatches from the egg, it retains its yolk sac.
It is called an alevin or sac-fry
These alevin are almost to the stage. ‘button-up’ stage.
Once the egg sac has been stage.
fry leave the gravel and become free- swimming.Fry
-Parr are older fry that show special markings called ‘parr marks’.
-Parr marks can be used as camouflage
Juveniles are small adults.
Most eventually lose their parr marks.
Adults spawning stage.
Females dig the depression (‘redd’) and lay their eggs. Males deposit the ‘milt’ with sperm to fertilize the eggs.
The female buries the fertilized eggs as she digs more of the redd.