Although white sturgeon feed on both plant and animal matter throughout their lives, adults are opportunistic predators, showing a distinct preference for fish and other animals. When schools of smelt, herring, or other forage species migrate into the estuary, sturgeon move in from the ocean to feed on them. Lampreys and ghost shrimp are other favorite foods. They consume many kinds of fish, dead or alive, and even move up the rivers to feed on carcasses of spawned-out salmon. They also eat sculpins, sticklebacks, suckers, and even their own kind.
White sturgeon grow slowly but live long.
Although growth rates vary from one estuary to another, most young fish grow to about 20 inches in five years and add two inches in length each following year, to about age 35. After that, they grow more in bulk than length. Spawning in fresh water, usually in May or June, 35-pound females lay nearly 700,000 eggs, while the largest specimens of 800 pounds or more can produce three to four million eggs, with a mass weight exceeding 200 pounds. Poor parents, the adults leave eggs unattended and let young fend for themselves. Juveniles consume mainly insect larvae, mysid shrimp, tiny crustaceans, mollusks, and other freshwater and marine invertebrates.