The gill cover has a convex upper margin. The adults are greyish-brown in color overlain with a mottled pattern and with darker fins.
And a maximum published weight of 400 kilograms (880 lb). The giant grouper is a species of shallow water and can be found at depths of 1 to 100 meters (3.3 to 328.1 ft).
Large specimens have been caught from shore and in harbors. They are found in caves and in wrecks while the secretive juveniles occur in reefs and are infrequently observed.
The adults are mainly solitary and hold territories on the outer reef and in lagoons. They have also been caught in turbid water over silt or mud sea beds by prawn fishermen.
The giant grouper is an opportunistic ambush predator which feeds on a variety of fishes, as well as small sharks, juvenile sea turtles, crustaceans and mollusks which are all swallowed whole. Fish which inhabit coral reefs and rocky areas favor spiny lobsters as prey and 177 centimeters (70 in) specimen taken of Maui in Hawaii had a stomach contents of two spiny lobsters and a number of crabs.
Fish living in estuaries environments in South Africa were found to be feeding almost exclusively on the crab Scylla errata. They are, however, curious and frequently approach divers closely.
They are not generally considered dangerous to humans but divers are advised to treat large specimens with caution and not to hand feed them. They are aggregate broadcast spawners, usually with several females per male.
Studies in captive populations suggest that the dominant male and female begin the spawning event as nearly the only spawners for the first day or two, but other members of the aggregation fertilize more eggs as the event progresses, with even the most recently turned males fathering offspring. Giant groupers are diabetic protogynous hermaphrodites, meaning that although some males develop from reproductively functional females other males start to produce sperm without ever having gone through a phase as a reproductive female.
The giant grouper is a highly valued food fish and is taken by both commercial and recreational fisheries. As well as the consumption of its flesh its skin, gall bladder and stomach are used in Traditional Chinese Medicine.
It is valued in Hong Kong as a live fish for the live reef food fish trade, especially smaller specimens. This species is cultured in agriculture and this practice is widespread but there is a restricted supply of juveniles, although hatcheries in Taiwan have produced captive bred juveniles, exporting some for to be grown on in other parts of South-East Asia.
Many of the fish produced in aquaculture are hybrids between this species and E. fuscoguttatus. IUCN Red List of Threatened Species.
“A study into parental assignment of the communal spawning protogynous hermaphrodite, giant grouper (Epimetheus lanceolatus)”. ^ Peter Palma; Akihito Nakamura; Garden XYZ Libunaoa; et al. (2019).
Although some populations are below target levels, U.S. wild-caught red grouper is still a smart seafood choice because it is sustainably managed and responsibly harvested under U.S. regulations. Fishing gear used to catch red grouper rarely contacts the ocean bottom and has minimal impacts on habitat.
They engulf prey whole by opening their large mouths, dilating their gill covers, rapidly drawing in a current of water, and inhaling the food. Large sharks and carnivorous marine mammals prey on adult red grouper.
Red grouper are found in the western Atlantic Ocean from Massachusetts through the Gulf of Mexico and south to Brazil. Annual catch limits are used for red grouper in the commercial and recreational fisheries.
These fisheries are closed when their annual catch limit is projected to be met. Both the commercial and recreational fisheries have size limits to reduce harvest of immature red grouper.
The commercial and recreational fishing seasons are closed from January through April to protect red grouper during their peak spawning period. To reduce by catch, there are restrictions on the type of gear fishermen may use and where they can fish.
Year-round and/or seasonal area closures for commercial and recreational sectors to protect spawning groupers. Groupers are a species of fish that belong to the Epinephrine subfamily of the family Serranidae.
If you are casting in the shallows, use jerk bait and retrieve it erratically to lure the fish out in the open. You will need heavy tackle, especially if there are a lot of rocks under the water where you are fishing and a braided line that can withstand the powerful pull of a caught grouper.
If you are using spinning tackle, make sure that the reel is heavy enough to withstand an 80 to 100-pound test mainline and a low gear ratio to give you more control. This tackle will come in handy when the panicking grouper fish tries to swim under a ledge to break the line.
For live bait, use pinkish, grunts, blue runner, sardines, and mullet. The grouper is a lean and moist fish that has a mild flavor, and the flesh is firm and flaky.