The diagrams elucidate the life cycle of the salmon, a large fish species, delineating its developmental stages from spawning to maturation.
Overall, the life cycle of the salmon encompasses several distinct phases, commencing with spawning in tranquil river waters, advancing through growth in currents, and culminating with the migration to the ocean before returning to their original habitat for reproduction.
The initial stage of the salmon’s life cycle occurs in the upper river, characterized by the spawning of eggs which are deposited onto small stones in slow-moving aquatic environments. This phase is pivotal as it lasts approximately six months, providing optimal conditions for the hatching of fry. Following hatching, the young salmon migrate downstream to the lower river, where they inhabit faster-flowing waters that are conducive to their growth and development.
In the lower river, young salmon undergo a significant transformation over a period of approximately four years, growing from fry into smolt fish, which typically reach lengths of between 70 and 76 centimeters. Subsequently, they migrate to the open sea, where they continue to mature for around one year. During this time, they further enhance their size and physiological capabilities. Ultimately, the adult salmon return to their upstream spawning grounds to reproduce, thereby closing the life cycle..