The life cycle of a salmon

The diagram illustrates various stages in the development of a salmon
The life cycle of salmon contains three main stages according to the places they are in, beginning with egg shape in the upper - river and ending with fully-grown salmon living in the open sea.
At the beginning of the process, the adult salmons upstream to the upper river with a slow-moving current then they choose a place hidden under the reed and small stones to lay eggs in order to keep the eggs well-protected. Before those eggs hatch and the newborn fishes turn into fries, the incubation lasts about approximately 5-6 months.
Afterward, the fries develop gradually in size, when reaching a certain length of 3-8 centimeters, they migrate downstream to the lower – river with a fast-flowing current and continue to develop there. After living in the lower river for about 4 years, the fries reach a new stage of development, they become bigger in size and turn into smolts. Finally, the smolt changes its living space once again into the open sea and reaches the fully-mature stage. A new life cycle will then continue.