The picture illustrates the stages involved in the life cycle of a salmon.
From an overall perspective, it is evident that the cyclical process comprises seven consecutive steps in total, commencing with the laying of eggs and culminating in the formation of a fully-grown salmon fish.
In detail, the life cycle of a salmon begins when the adult salmon lays a cluster of fish spawn in the water. After that, the eggs experienced a three-month period before hatching into alevins. In the following stage, the alevin relies heavily on feeding off its yolk sac for several weeks prior to turning into the fry which is five to 10 weeks old and has the ability to swim. As it grows older for a number of months, the fry is converted into parr during the next step and begins to have “finger” markings.
In the remaining phase, the salmon experiences a series of significant transformations until the end of the cyclical process. In particular, the parr continues to grow bigger and change into the smolt when it reaches around one to three years old, which is ready to group and head out to sea for food. In the subsequent stage, the adult salmon keeps developing in size and spends one to six years at sea. After a total of about 8 years from the start, the female spawning adult dies within only two weeks after reproducing a new cluster of eggs, thereby restarting the cycle.