1. Trout Life Cycle

3. Egg The egg is the first step in the life cycle of the trout.

4. Just after fertilization eggs are very soft and sticky. They are called ‘green’ eggs.

5. The source of energy for the embryo comes from the yolk. The developing embryo uses the yolk as its food.

7. Eyed-Egg 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.

8. Zebra fish embryo

9. Hatching

11. Alevin or Sac Fry When the trout hatches from the egg, it retains its yolk sac. It is called an alevin or sac-fry

12. The alevin also use the egg yolk as its food source.

15. The alevin remain in the gravel until they reach the fry stage.

16. These alevin are almost to the ‘button- up’ stage.

17. Fry  Once the egg sac has been absorbed, the fry leave the gravel and become free- swimming.

18.  The fry now has to forage for food.

19. Parr -Parr are older fry that show special markings called ‘parr marks’. -Parr marks can be used as camouflage

20. Parr marks can help identify small trout and salmon. Chinook Steelhead Sockeye

21. Juveniles Juveniles are small adults. Most eventually lose their parr marks.

22. Adult rainbow

23. Adults spawning Females dig the depression (‘redd’) and lay their eggs. Males deposit the ‘milt’ with sperm to fertilize the eggs.

25. Redd

26. Redd The female buries the fertilized eggs as she digs more of the redd.

28. How redds are built

29. …and it starts again….