How does the age of maturity differ between anadromous and landlocked alewife populations?

In anadromous populations of the alewife, sexual maturity is typically reached at three to four years of age, at which point the fish measure approximately 150 to 170 mm (6 to 6.75 inches) in length.1

In contrast, landlocked populations of the alewife mature significantly earlier, reaching breeding age at one to two years old. These individuals are also smaller at maturity, typically measuring between 95 and 100 mm (3.75 to 4 inches) in length.1