Complete each sentence choosing the correct option
Typically, salmon are anadromous. They hatch in fresh water, migrate to the ocean, then return to fresh water to reproduce. However, populations of several species are restricted to fresh water through their lives. Folklore has it that the fish return to the exact spot where they hatched to spawn. Tracking studies have shown this to be mostly true. A portion of a returning salmon run may stray and spawn in different freshwater systems; the percent of straying depends on the species of salmon.Homing behavior has been shown to depend on olfactory memory.Salmon date back to the Neogene.