Like char, salmon belong to the Salmonidae family. Typical is the shiny silver, dark grey back, and lighter belly. The colour of the salmon changes during their lifetime due to hormonal influences. They grow to a maximum length of 1.50 meters and can weigh 35 kilograms. Farmed salmon can be recognised by their dorsal fins, which are curved in contrast to the typically developed fins of wild salmon. The consumer usually identifies salmon by its typical light red, pink meat.
Born as freshwater fish, young salmon eventually migrate to the sea when they are old enough and the conversion to salty sea fare does not pose any problem. Salmon reach sexual maturity at the age of three to six years then leave the marine habitat and journey up river to spawn. They usually have to overcome great obstacles such as swimming against the current and possibly passing through waterfalls or man-made dams. Nevertheless, they swim very long distances and sometimes cover 100 kilometres a day. During this journey the salmon does not feed. Spawning season is from October to December. The young are identified by red spots on their body and are called grilse.