Life history parameters of chub mackerel (Scomber japonicus) from two areas off Chile

Age, growth, maturity, and natural mortality estimates were made for chub mackerel (Scomber japonicus Houttuyn, 1782) captured off the Chilean Pacific coast. The von Bertalanffy growth parameters for combined sexes from north and central-south areas were L_∞ = 36.9 cm, k = 0.22 yr ^-1, and t₀ = -1.35 yrs, and L_∞ = 40.0 cm, k = 0.23 yr^-1, and t₀ = -1.34 yrs, respectively. The spawning period in the northern area ranged from November to February of each year; it was restricted to January and February in the central-south area. The size at maturity (L_m50%) estimated for the north and central south areas, respectively, were 25.1 and 29.6 cm fork length (FL) in males, and 25.9 and 28.1 cm FL in females. Natural mortality was similar in the two areas: 0.45 yr^-1 in the north and 0.46 yr^-1 in the central-south region. Results support the existence of two stocks off Chile's southeastern coast.