Prior to the construction of dams on the Missouri, pallid sturgeon migrated hundreds of miles upstream to spawn, and sought out rocky or hard surfaces to deposit hundreds of thousands of eggs. One female pallid sturgeon caught in the upper Missouri River was estimated to be carrying 170,000 eggs, representing over 11 percent of its total body weight. After fertilization, pallid sturgeon eggs hatch in 5 to 8 days, after which the larvae drift back downstream for several weeks. As the larvae develop tails, they seek out slower-moving waterways and slowly mature over a period of a dozen years. The rate of survival to maturity for pallid sturgeon larvae is extremely low, and of the hundreds of thousands of eggs spawned, only a few live to adulthood.