Growth and Overfishing Indicators Applied to the Protandrous Hermaphrodite Fat Snook ( Centropomus parallelus ) in the South Atlantic

The fat snook Centropomus parallelus is a protandrous hermaphrodite teleost of artisanal and recreational value in the South Atlantic, vulnerable to fishing pressure and size‐selective gears. We evaluated exploitation status using size and age based overfishing indicators from recreational fishing championships and artisanal landings along the southern Brazilian coast, from southern São Paulo to northern Rio Grande do Sul. Age and growth parameters were estimated from 209 sagittal otoliths, and size‐frequency data from 9708 individuals sampled between 2006 and 2024. Ages ranged from 0 to 13 years (16–76 cm), and growth followed the von Bertalanffy model ( L ∞ = 57.92 cm, k = 0.17 year −1 , t 0 = −2.01 years). The average age at first maturation ( A 50 ) was 1.8 years, while sex change occurred at 4.4 years and 31.7 cm ( Ls 50 ). Size‐based indicators revealed few mega‐spawners and a high exploitation rate (44%) by artisanal fisheries. We recommend adopting Ls 50 as the minimum capture size to protect sex‐changing individuals and sustain reproductive capacity.