The mother trout lays her eggs in a nest in the ground, which the male then covers with sand. The eggs hatch into alevin trout, which then develop into fry as they grow to resemble miniature adult trout. The fry then become parr trout, developing distinctive markings and able to stay in freshwater or migrate to the sea to become sea trout. The trout in the document have survived past the alevin stage, with their yolk sacs shrinking each time the narrator checks on them.