The basic life pattern of the Salmonidae begins when, within the first year or two of life, the fish travels downstream to the sea, where it grows to its full size. After reaching maturity (one to nine years) it returns to its hatching site to spawn. The Pacific salmon are famed for their grueling journeys of hundreds of miles to their headwater breeding grounds. When they begin this trip they are in prime condition, but they cease eating when they leave the sea and arrive months later, exhausted and battered by their fight upstream against swift currents and over falls. Those that survive the trip and escape fishermen and predatory animals spawn with their last strength and then die. These salmon are taken at the mouths of large rivers, as they begin their upstream migration. The Atlantic salmon and the trouts spawn more than once. Most trouts migrate to the sea if there is a cold-water connection, but also will sometimes live and reproduce if landlocked.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.