Over winter, the eggs hatch into pretty modest salmon termed alevin which continue to have their yolk sac hooked up. Alevins remain near to the redd for a couple months hiding from predators within the spaces between gravel. During this phase they consume the yolk sac and grow in size. https://ricardokixky.blogdiloz.com/30206486/new-step-by-step-map-for-atlantic-salmon-fresh-water