ABSTRACT
This chapter presents information on the diet and feeding behaviors of groupers (Serranidae, Epinephelinae). These warm-temperate and tropical predators (from <30 cm to >250 cm TL) feed on fish, crustaceans and cephalopods, except Paranthias which consumes zooplankton. Piscivory is observed in Anyperodon, Gonioplectrus, Gracila, Variola and most Mycteroperca species, during all their life cycle. An ontogenetic shift in diet occurs in other species (e.g. Cephalopholis, Epinephelus, Plectropomus) with a decrease in crustacean consumption and an increase in fish and cephalopod predation with size, often related to size-dependent changes of habitat. Mid-water piscivorous groupers generally pursue actively their prey, while groupers feeding on benthic prey are ambush predators. Groupers may be active during the day, at night or during twilight periods, and weak seasonal and geographic variations are recorded. Analyses of C and N stable isotopes of muscles indicate that groupers are positioned at mid-trophic levels, while only large-sized piscivorous epinephelids may be considered as apex-predators. A positive relationship between abundances of groupers and those of their prey is observed in temperate and tropical ecosystems. A high abundance of groupers is thus an indicator of healthy food webs.
