Fig. 1. Illustration of the “Critical Period” as hypothesized by Hjort (1914, 1926). Failing to find suitable prey in sufficient quantity, >90% mortality occurs soon after larvae absorb their yolk and initiate feeding (cohort B). In this example, the daily mortality rate, except for the critical period, is M = 0.1. Recruitment at 100 days post-hatch differs by 50-fold in cohorts experiencing (B) and not experiencing (A) a critical period. (Modified from Houde, 2002, Fig. 3.4).