This diagram shows the life cycle of the salmon, a species of large fish that is born and grows in rivers and spends its adult life in the open sea.
Starting as an egg in the upper river, the salmon then grows into a smolt in the lower river. Finally, it moves to the open sea and gives birth to new lives there.
Firstly, a salmon is incubated from a small egg between tiny stones in the upper river, where the water flow is modest. It takes the fish about 5 to 6 months to grow into a ‘fry’. Then, starting at a length of 3 to 8 centimeters, the fry spends approximately 4 years growing bigger and stronger in the fast-flowing lower river.
Finally, after becoming big enough, at a size of 12 to 15 centimeters, the so-called ‘smolt’ moves to the open sea. It spends around 5 years there, during which it may grow into an ‘adult salmon’ of 70 to 76 centimeters in length. New salmon eggs are generated, and the salmon move back to the upper river, where the life cycle of a salmon begins.