Largemouth bass grow 4 to 6 inches during their first year, 8 to 12 inches in two years, 16 inches in three years. They are usually green with dark blotches that form a horizontal stripe along the middle of the fish on either side. The underside ranges in color from light green to almost white. They have a nearly divided dorsal fin with the anterior portion containing nine spines and the posterior portion containing 12 to 13 soft rays. Their upper jaw reaches far beyond the rear margin of the eye. Adult largemouth bass are the top predators in the aquatic ecosystem.