The diagram illustrates the different stages of the life of the salmon – a type of large fish.
From the diagram, it can be deduced that the salmon can thrive in either fresh water or sea water depending on which stage of life they are at.
First, the salmon lay their eggs among reeds in the slow moving water of the upper part of a river. After hatching, the fish – called ‘fry’ – swim around this part of the river for 5-6 months until reaching a size of 3-8cm. At this point, the fry make their way to the lower part of the river, where the water flows fast. They remain here for approximately 4 years until maturing into smolt, which are 12-15cm long.
The smolt subsequently swim out to the open sea and continue to grow rapidly for the next 5 years into adult salmon, reaching 70-76cm in length. The adult salmon finally swim back up the river from whence they came to spawn among the reeds in the slow-moving water. The cycle is complete.