This species inhabits coral reefs, especially exposed reef front areas. It primarily feeds on a variety of small and juvenile reef fishes (Meyer and Dierking 2011). The Peacock Grouper occurs in social groups comprised of a single male and haremic females. Male territory size is positively associated with fish size (Pears 2005). Each group occupies a specific area (up to 2,000 m²) that is defended by the territorial male and subdivided into secondary territories, each inhabited by a single female (Shpigel and Fishelson 1991). The demography of this species is highly plastic and shows great variation over its distribution, especially in terms of maximum longevity and maximum size. In American Samoa, maximum fork length ranged from 30.5 to 36 and maximum age from 21 to 28 years (J. Choat pers. comm.). In the Great Barrier Reef, maximum fork length was 47 cm and maximum age was 40 years (Pears 2005). In Moorea, maximum fork length was 32.8 cm and maximum age 25 years. In the Marquesas, maximum fork length was 36.5 cm and maximum age was 27 years (J. Choat pers. comm.). In the main Hawaiian Island chain, maximum fork length ranged from 41.1 to 49.6 cm and maximum age from 13 to 25 years with a mean of 19 (Donovan et al. 2013). In the Seychelles, maximum fork length was 37.8 cm and maximum age was 19 years (Pears 2005). In the Hawaiian islands, this species has a reduced generation time and rapid population turnover. It exhibits monandric protogyny in Hawaii, and spawns from May to October with an age and size at sexual maturity of 1.2 years and 20 cm fork length (Schemmel et al. 2016).
