The diagrams illustrate the life cycle of a salmon, highlighting three main stages: fry, smolt, and adult salmon.
Initially, salmon eggs hatch in the upper river, a slow-moving water body with reeds and small stones. This stage lasts approximately 5-6 months. The newly hatched fish, termed “fry,” measure between 3-5 cm in length.
Subsequently, the fry migrate to the lower river, characterized by faster-flowing water, where they continue to grow for about 4 years. During this period, they transition into the “smolt” stage, reaching a length of 12-15 cm. The smolts then travel towards the open sea.
In the open sea, the salmon spend approximately 5 years maturing into adults, growing to a length of 70-76 cm. Once they reach full maturity, the adult salmon migrate back to the upper river to spawn, thereby completing their life cycle.
In summary, the salmon’s life cycle encompasses significant growth and development in diverse aquatic environments, from the upper river to the lower river and finally the open sea, before returning to their birthplace to reproduce.