Growth of the Pacific pomfret, Brama japonica: a comparison between otolith and length–frequency (MULTIFAN) analysis

Abstract

Age and growth of the Pacific pomfret, Brama japonica, were independently estimated with presumed daily increments within otolith microstructure and MULTIFAN analysis of length–frequency distributions obtained from drift net fisheries. Likelihood ratio tests detected significant differences between sexes and geographic areas in von Bertalanffy parameter estimates from otolith analysis. Otolith interpretations indicated that the species is short lived (age 3+), fast growing (growth coefficient (K) > 1.1), and fully recruited to the North Pacific squid drift net fishery at < 1 yr old. Back-calculated hatching dates indicate a protracted spawning period. MULTIFAN models fit the length–frequency data with an assumption of both annual and biannual recruitment. Growth parameter estimates were asymptotic fork length (FL∞) = 49.9 cm, K = 0.57 for an annual cohort model, and FL∞ = 49.4 cm, K = 1.0 for a biannual cohort model. The growth model derived from otolith increment counts is closer to the MULTIFAN model that assumes biannual length–frequency modes, rather than annual modes.