1. Salmon 1.Salmon eggs are laid in freshwater streams typically at high latitudes. The eggs hatch into alevin or sac fry. The salmon spend about one to five years (depending on the species) in the open ocean where they gradually become sexually mature. Juvenile salmon eat zooplankton, and larval and adult invertebrates. When migrating, salmon are particularly susceptible to predation, so they seek deep areas to quickly swim into. Salmon school in the ocean for protection, confusing predators with their flashy sides, and possibly being mistaken for a large predator. Physical changes vary between the species of salmon and are dependent on the amount of time between a salmon's entry into fresh water and spawning. 2.Could not find answer. 3.Most salmon can lay a couple thousand eggs, but sometimes even up to 5,000 eggs in one hatching covering almost 30 square feet. Most females have about seven cycles of egg laying before their supply becomes exhausted.