Life history of the humpnose big-eye bream Monotaxis grandoculis

This study provides estimates of growth rate, longevity, maturity, spawning seasonality and mortality for Hawai'i's only lethrinid, the humpnose big-eye bream (known as Mū in Hawai'i) Monotaxis grandoculis, a commercially and recreationally important species in Hawai'i and throughout the Indo-Pacific. M. grandoculis reaches maturity at 303 mm fork length or 3.6 years of age for both sexes. Males were significantly larger than females for a given age. The von Bertalanffy growth parameters for males and females were L_∞  = 506 mm fork length and von Bertalanffy growth coefficient (K) = 0.24 year^-1 , and L_∞  = 427 mm fork length and K = 0.33 year^-1 , respectively. Both males and females reached ages over 20 years old, with a maximum age of 23 years. M. grandoculis had a distinct spawning season from May through August with corresponding elevated female gonadosomatic index. An age-based multinomial catch curve indicated that the commercial exploitation rate (natural mortality/fishing mortality) was 0.48 year^-1 , which is considered below the overfishing limit.