In addition, the species classified in the small genera Hyperion, Completes, Dermatologist, Graciela, Scotia, and Trio are also called 'groupers'. However, some hamlets (genus Affected), the hinds (genus Cephalopods), the lyre tails (genus Various) and some other small genera (Gonioplectrus, Nippon, Paranoia) are also in this subfamily, and occasional species in other serrated genera have common names involving the word grouper “.
They can be quite large, and lengths over a meter and the largest is the Atlantic Goliath grouper (Epimetheus Tamara) which has been weighed at 399 kilograms (880 pounds) and a length of 2.43 m (7 ft 11 1 2 in), though in such a large group, species vary considerably. They do not have many teeth on the edges of their jaws, but they have heavy crushing tooth plates inside the pharynx.
They habitually eat fish, octopuses, and crustaceans. Reports of fatal attacks on humans by the largest species, such as the giant grouper (Epimetheus lanceolatus) are unconfirmed.
They also use their mouths to dig into sand to form their shelters under big rocks, jetting it out through their gills. The word grouper is from the Portuguese name, group, which has been speculated to come from an indigenous South American language.
In New Zealand, “groper” refers to a type of wreck fish, Poly prion oxygenate, which goes by the Mori name haiku. In the Middle East, the fish is known as hammer ', and is widely eaten, especially in the Persian Gulf region.
The species in the tribes Grammistini and Diploprionini secrete a mucus like toxin in their skin called Rammstein and when they are confined in a restricted space and subjected to stress the mucus produces a foam which is toxic to nearby fish, these fishes are often called soap fishes. Jordan, 1923 Tribe Epinephrine Sleeker, 1874 Aethaloperca Fowler, 1904 Affected Bloch & Schneider, 1801 Anyperodon Gunther, 1859 Cephalopods Bloch & Schneider, 1801 Chromites Swanson, 1839 Dermatologist Gill, 1861 Epimetheus Bloch, 1793 Gonioplectrus Gill, 1862 Graciela Randall, 1964 Hyporthodus Gill, 1861 Mycteroperca Gill, 1862 Paranoia Guillemot, 1868 Plectropomus Pen, 1817 Scotia J.L.B.
Smith, 1964 Trio Randall, Johnson & Lowe, 1989 Various Swanson, 1839 The largest males often control harems containing three to 15 females.
Groupers often pair spawn, which enables large males to competitively exclude smaller males from reproducing. As such, if a small female grouper were to change sex before it could control a harem as a male, its fitness would decrease.
If no male is available, the largest female that can increase fitness by changing sex will do so. Gonochorism, or a reproductive strategy with two distinct sexes, has evolved independently in groupers at least five times.
The evolution of gonochorism is linked to group spawning high amounts of habitat cover. Both group spawning and habitat cover increase the likelihood of a smaller male to reproduce in the presence of large males.
Fitness of male groupers in environments where competitive exclusion of smaller males is not possible is correlated with sperm production and thus testicle size. Gonochoristic groupers have larger testes than protogynous groupers (10% of body mass compared to 1% of body mass), indicating the evolution of gonochorism increased male grouper fitness in environments where large males were unable to competitively exclude small males from reproducing.
Many groupers are important food fish, and some of them are now farmed. Unlike most other fish species which are chilled or frozen, groupers are usually sold live in markets.
Groupers are commonly reported as a source of Ciguatera fish poisoning. DNA barcoding of grouper species might help in controlling Ciguatera fish poisoning since fish are easily identified, even from meal remnants, with molecular tools.
In September 2010, a Costa Rican newspaper reported a 2.3 m (7 ft 7 in) grouper in Cieneguita, Limón. The weight of the fish was 250 kg (550 lb) and it was lured using one kilogram of bait.
In November 2013, a 310 kg (680 lb) grouper had been caught and sold to a hotel in Dong yuan, China. ^ a b c d e Richard van der Loan; William N. Scholar & Ronald Cricket (2014).
^ Share, Redoubt; Honer, Andrea; Ait-El-Djoudi, Karim; Cricket, Hans (2006). “Interspecific Communicative and Coordinated Hunting between Groupers and Giant Moray Eels in the Red Sea”.
“Rammstein, the skin toxin of soap fishes, and it significance in the classification of the Grammistidae” (PDF). Publications of the Set Marine Biological Laboratory.
^ Scholar, William N. ; Cricket, Ron & van der Loan, Richard (eds.). A phylogenetic test of the size-advantage model: Evolutionary changes in mating behavior influence the loss of sex change in a fish lineage.
Estimates of body sizes at maturation and at sex change, and the spawning seasonality and sex ratio of the endemic Hawaiian grouper (Hyporthodus Quercus, f. Epinephelidae). Constant relative age and size at sex change for sequentially hermaphroditic fish.
A new version of the size-advantage hypothesis for sex change: Incorporating sperm competition and size-fecundity skew. Sex change in fishes: Its process and evolutionary mechanism.
Evidence of gonochorism in a grouper, Mycteroperca rosacea, from the Gulf of California, Mexico. ^ Molly, P. P., N. B. Goodwin, I. M. Cote, J. D. Reynolds and M. J. G. Gage.
Sperm competition and sex change: A comparative analysis across fishes. ^ Crib, T. H., Bray, R. A., Wright, T. & Michelin, S. 2002: The trematodes of groupers (Serranidae: Epinephrine): knowledge, nature and evolution.
^ Justine, J.-L., Beveridge, I., Box shall, G. A., Bray, R. A., Morale, F., Triples, J.-P. & Whittington, I. D. 2010: An annotated list of parasites (Isopod, Coppola, Monotone, Diogenes, Custody and Nematode) collected in groupers (Serranidae, Epinephrine) in New Caledonia emphasizes parasite biodiversity in coral reef fish. Folio Parasitologica, 57, 237-262. Doi : 10.14411/fp.2010.032 PDF ^ “Most consumers prefer to purchase live groupers in fish markets”.
^ Schooling, C., Kissinger, D. D., Detail, A., Fraud, C. & Justine, J.-L. 2014: A phylogenetic re-analysis of groupers with applications for ciguatera fish poisoning. ^ ^ “Photos: Fishermen catch wildly huge 686-pound fish, sell it to hotel”.
The giant grouper has a robust body which has a standard length equivalent to 2.4 to 3.4 times its depth. The dorsal profile of the head and the intraorbital area are convex, The properly has a rounded corner and a finely serrated margin.
The gill cover has a convex upper margin. The adults are greyish-brown in color overlain with a mottled pattern and with darker fins.
The giant grouper can grow to huge size with the maximum recorded standard length being 270 centimeters (110 in), although they are more common around 180 centimeters (71 in). 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.
Groupers of the world (family Serranidae, subfamily Epinephrine). “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). “Reproductive development of the threatened giant grouper Epimetheus lanceolatus “.