A sexually mature female salmon produces around 10 000 eggs which are fertilized with milt from a male.

It takes 500 degree days from fertilization to hatching. The hatched fry gets all its nutrition from the yolk. After reaching a weight of about 0,2 gram, it starts to eat dry pellet feed, and grows quickly.

The fingerling develops dark spots in the skin (fingerling markings) and is still adapted to a fresh water existence.

The weight doubles about every two weeks. Major physiological changes (smoltification) starts – in order to adapt to a life in salt water.

It takes the smolt about 12–18 months to reach a final weight of 4–6 kilos. For each kilo of salmon produced, only 1 kilo of feed has been used.