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.