Travel to Alaska with Chris Kratt to learn about the unique life cycle of the sockeye salmon. All salmon begin life as a fertilized egg in a freshwater gravel nest, called a redd. Once hatched, sockeye salmon migrate to the ocean to eat and grow, ultimately returning to freshwater to lay their own eggs. The journey back to freshwater requires a difficult upstream swim, and salmon undergo some major physical changes along the way. Sockeye develop a deep red coloration to attract mates, and male sockeyes' jaws become larger and hooked in appearance for defense. Male salmon also develop large humps on their backs, primarily to attract females.