The diagrams provided illustrate the life cycle of the salmon, a notable species of large fish, detailing its development from eggs to adulthood.
In summary, the life cycle of the salmon is characterized by four distinct stages, commencing with the spawning of eggs in freshwater and culminating with the maturation of adult salmon in the sea before their return to freshwater for spawning.
The initial stage of the life cycle occurs in the upper reaches of rivers, where female salmon lay their eggs in slow-moving, sheltered waters. This critical phase, which lasts approximately six months, sees the eggs protected by natural elements such as reeds and pebbles, facilitating their survival against predators. Upon hatching, the young salmon, referred to as ‘fry,’ measure between three to eight centimeters in length. These fry subsequently migrate downstream to faster currents, where they experience a growth phase lasting about three to six months, during which they transform into ‘smolt’ and reach lengths of twelve to fifteen centimeters.
The maturation of the smolt occurs during their migration to the open sea, signifying the next phase of their life cycle. After spending roughly one year in saltwater, the juvenile salmon undergo significant growth, attaining lengths of approximately seventy to seventy-six centimeters. Upon reaching maturity, the adult salmon embark on a remarkable journey back to their natal rivers to spawn. This final stage not only concludes the life cycle of the salmon but also initiates the sequence anew as they lay their eggs in the same freshwater environments where their life began.