The cycle begins with the broodstock. These are the parent fish, selected for characteristics such as growth, disease resistance, maturation and colour. They are held in a hatchery in large freshwater tanks where they become sexually mature and ready to spawn. Eggs from the females 
are mixed with milt (sperm) from the males to produce fertilised eggs. Viable eggs are referred to as eyed eggs because as they develop, the embryonic eye becomes visible. Eyed eggs are kept in incubation tanks 
in fresh water at a steady temperature. There are around 5,000 eggs in a litre. The rate at which they develop depends on the water temperature.
When the eggs hatch, tiny fish emerge in a form known as alevins. The alevins have a yolk sac that provides nutrition. Initially the sac is three-quarters of the weight of the alevin and lasts several weeks, until they are large enough to feed themselves. At this stage, the fish are referred to as fry and are about 25mm in length. Still in fresh water, they now begin to receive specially prepared feed. Because the fry are relatively large (compared with many marine fish species), they adapt easily to manufactured feeds. Throughout their life, the fish readily eat specially made dry feed pellets that match their nutritional requirements, keeping them healthy, active and growing.
When the salmon fry are about six grams, they are moved to larger freshwater tanks 
or to an open net cage in a lake. The fish now develop into parr, which are green-brown in colour and with distinctive fingerprint markings on their sides. This is a phase in which the fish grow rapidly in the right conditions, though low temperatures may slow this. They reach 60–80 grams and a length of around 120mm and are ready to move on to the smolt stage.