Comparative Demography of Two Groupers Epinephelus maculatus and Epinephelus polyphekadion From the Republic of the Marshall Islands

Groupers (Family: Epinephelidae) are important for local fisheries and food security throughout the Indo‐Pacific Island region, yet site‐specific life‐history data required for sustainable management are largely absent. This study provides a comparative demography of two sympatric species, the highfin grouper Epinephelus maculatus and the camouflage grouper Epinephelus polyphekadion , from the Republic of the Marshall Islands (RMI). Both species exhibit moderate longevity, with E. maculatus and E. polyphekadion reaching maximum observed ages of 17 and 24 years, respectively. The von Bertalanffy growth profiles revealed divergent life‐history trajectories: E. maculatus grew rapidly ( L ∞ = 43.5 cm, K = 0.500 year −1 ) and matured early ( A 50 = 3.4 years), whereas E. polyphekadion followed a slower trajectory ( L ∞ = 46.8 cm, K = 0.198 year −1 ) with a significantly delayed maturity ( A 50 = 6.0 years). Histological analysis confirmed protogynous hermaphroditism in E. maculatus , with evidence of prematurational sex change observed in E. polyphekadion . Our findings provide the first evidence‐based biological baselines for these species for RMI. These data are critical for ensuring the long‐term resilience of reef‐associated fisheries in the Indo‐Pacific atoll ecosystems.