The illustration demonstrates various stages of life cycle of salmon which is one of the big fish species.Overall, there are three distinct Stages in the figure about life cycle of salmon. It beginnings in the upper river under the reeds and ending at the same starting point after the passage of almost ten years.
Initially,the salmon begin life as eggs in upper river with slow moving among reeds and pebbles. After approximately six months, the newly hatched salmon called fry immigrate to the lower river. this part of river has a fast flow, making it a convenient place for Salmon for the next four years.
To enter the next stage, having grown to smolt (12-15 cm long), the salmon swim down to the open sea to live for another five years. In that place they grow much faster compared their life in the river, ultimately reaching 76 cm which is five times bigger than the smolt in lower river. The adult salmon swim back to the orginal place to lay eggs and the cycle starts anew.