Maturation and growth of Pacific Mackerel, Scomber japonicus Houttuyn

The maturation of Pacific mackerel has never been documented clearly. Analysis of data reveals spawning can occur from March through October, but the majority takes place from April through August. During this April through August period, 22.5%, 65.7%, 75.1%, 84.7%, 84.2%, and 87.5% of the female fish were mature or maturing for Age Groups I, II, III, IV, V, and VI+ respectively. A von Berta1anffy growth curve and a weight-length curve were calculated. The weight-length curve was found to differ significantly from a curve previously published. (21pp.)