Groupers vacuum prey and some switch sex to run a harem
Groupers are stout epinephelid reef predators built to gulp, not sprint. A huge mouth and gills create suction that inhales fish, octopus, and crustaceans from afar. Most mature as females first; the largest may become males that monopolise harems of up to fifteen females—unless habitat and spawning style favour staying two separate sexes.
Long treated as a serranid subfamily, they now stand as Epinephelidae. The everyday label usually means Epinephelus and Mycteroperca, plus coral groupers in Plectropomus; the family name nods to a cloudy eye membrane noted by early European describers. Bodies often exceed a metre. The Atlantic goliath has hit three hundred ninety-nine kilograms and two point four three metres. Pharyngeal tooth plates crush what sparse jaw-edge teeth do not shear; some species ambush, others roam. Roving coralgroupers sometimes hunt with giant morays, and groupers are among the few fishes known to eat invasive red lionfish.
Protogynous monandry is the default: fish become female around three kilograms after growing about a kilogram a year, then the biggest female may change sex if no male holds the site. Pair spawning lets large males shut smaller ones out, so early sex change can lower fitness. Gonochorism evolved independently at least five times where group spawning and cover let small males succeed; those species carry testes near ten percent of body mass versus about one percent in protogynous kin. Unconfirmed tales of fatal attacks by giants such as Epinephelus lanceolatus circulate, but markets still sell many species live, and ciguatera risk has pushed DNA barcoding of leftovers.
Regional names track the catch: Australian groper, Filipino lapu-lapu or pugapo, Malay kerapu, Gulf hammour, Latin American mero. Record news has claimed one hundred eighty-kilogram fish off Malaysia, a two-point-three-metre Costa Rican catch, and aquarium scenes of groupers swallowing reef sharks whole.
Source: Grouper
