The life cycle of the salmon involves a total of seven stages, starting with the form of an egg and finishing with the spawning adult phase. Each stage is different and has its own characteristics.
To start the cycle, the eggs are deposited in fresh water by spawning adults. A total of three months is required before they hatch. The alevins come out of these eggs; this is the simplest living form and their diet consists mainly of the yolk-sac. After five to ten weeks of feeding, they grow up into a fry, developing a few typical characteristics, such as fins and tale, which allow them to swim. When a fry is several months older, becomes a parr; this form differs from the previous one in its “finger” marks, which appear all over its back. One to three years later, the parr evolves into a smolt, this is when salmons form groups with others and head out to sea. Immediately after, they turn into adults, living for one to eight years at sea. Finally, they reach their reproductive stage, becoming spawning adults and dying two weeks after the spawn.
As seen, salmons are marine creatures with a long and complex life cycle. Life expectancy of these creatures is about eight years, but it could be shorter, depending on how much time lasts each stage.