The provided diagrams illustrate the complex life cycle of the salmon, a large species of fish. Overall, the salmon's life is a cyclical journey spanning approximately ten years, beginning with eggs laid in the upper river and culminating in adult salmon returning to the same freshwater environment to spawn after significant time spent developing in rivers and maturing in the open sea. The process commences when adult salmon deposit their eggs amongst reeds and small stones in the slow-moving upper reaches of a river. These eggs incubate for around five to six months before hatching into 'fry', which measure between 3 and 8 centimetres. The fry subsequently move downstream to the fast-flowing lower river, where they reside for approximately four years. Following this extended period, the fry mature into 'smolt', growing to about 12-15 centimetres in length. At this stage, they undertake a migration to the open sea, where they spend a substantial period of roughly five years. Here, they develop into large 'adult salmon', reaching an impressive size of 70-76 centimetres. Finally, to complete the cycle, these mature salmon navigate back upstream from the sea to the original spawning grounds in the upper river, where they lay their own eggs.
Key Vocabulary