Salmon divergence. Salmon eggs are laid in freshwater streams typically at high latitudes. The eggs hatch into alevin or sac fry. The fry quickly develop into parr with camouflaging vertical stripes. The parr stay for six months to three years in their natal stream before becoming smolts, which are distinguished by their bright, silvery colour with scales that are easily rubbed off. Only 10% of all salmon eggs are estimated to survive to this stage. The smolt body chemistry changes, allowing them to live in salt water. While a few species of salmon remain in fresh water throughout their life cycle,
Atlantic salmon smolt, grilse, grilt, kelt, slink, and spring salmon. Atlantic salmon that do not journey to sea are known as landlocked salmon or ouananiche. Atlantic salmon are the largest species in their genus, "Salmo". After two years at sea, the fish average in length and in weight. But specimens that spend four or more winters feeding at sea can be much larger. An Atlantic salmon netted in 1960 in Scotland, in the estuary of the river Hope, weighed , the heaviest recorded in all available literature. Another netted in 1925 in Norway measured in length, the longest Atlantic salmon on record.