Fifteen-spined sticklebacks grow up to 20 centimeters long. In European coastal waters, they live mostly in areas rich in seaweed and eelgrass. They eat primarily shrimp. Fifteen-spined sticklebacks were common in the Wadden Sea until 1932, however when the eelgrass fields disappeared, the fifteen-spined stickleback have also practically vanished here. The male makes a nest from plant material on the sea bottom. The female lays 150 to 200 eggs in the nest and dies soon afterwards. The males take care of the brood until the eggs hatch.