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 “.
Nonetheless, the word grouper on its own is usually taken as meaning the subfamily Epinephrine. Groupers are Telecasts, typically having a stout body and a large mouth.
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, W. N.; R. Cricket & R. van der Loan (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”.
Wiki source has the text of the 1905 New International Encyclopedia article Grouper “. Lowerre-Barbieri S, Menéndez H, Pickford J, Switzer TS, Barrier L, Koenig C (2020) Testing assumptions about sex change and spatial management in the protogynous gag grouper, Mycteroperca microbes.
Gag exhibited complex spatial ecology; females formed pre-spawning aggregations before migrating to deep-water spawning sites, which overlapped with locations where males were sampled year-round. Sex change occurred in only 0.48% of the samples taken, occasionally in small fish and before, during, and after the spawning season.
The gag’s unique life history and spatial ecology pattern makes it difficult to understand the best way to measure stock productivity based off reproductive parameters. We integrated our directed sampling data with gag data from Fri programs Fisheries Independent Monitoring and Fisheries Dependent Monitoring and also from Captain Ed Walker, a local commercial fisherman, who kept a portion of his catch for biological sampling prior to their sale.
A large, integrated data set gave more power to test the following hypothesis about where and when sex change occurs and the effectiveness of spawning reserves to protect male gag. Sex change occurs only on the spawning grounds and is cued by a fish’s internal clock or occurs above a minimum size threshold, 800 mm/31.5 in total length (TL) and is cued by male sex ratios on the spawning grounds.
Histology is the science of producing stained sections of preserved tissue on glass slides that can be examined under a microscope. Spatial ecology, how fish were distributed over space We hypothesized that female gag would form pre-spawning aggregations prior to migrating to deep-water spawning sites, where males remain year-round.
Our results supported these hypotheses and showed that gag exhibit clear depth preferences with life stage, sex, and spawning (Figure 3). While behavior and migrations associated with spawning accompanied by changes in reproductive organs (gonads) in gag extends from December through May, we found that actual spawning only occurred at our study sites from February 1st through April 18th.
Respawning aggregating behavior consistently occurred at the shallow sites that Captain Ed Walker targeted, where he captured fish in November and as late as mid-February. Sex ratio We hypothesized within the MPA, that male abundance would have increased to 15%, as indicated by previous modelling efforts.
For all months with samples taken in the Madison Swanson MPA (December to May) there was an 11% male sex ratio. During spawning season is when most mature males and females are in the same location, so a 5% male sex ratio is what we concluded to be a more accurate representation of the population compared to outside the spawning season, when some females migrate back to shallower water.
Although we do not have the data to estimate the optimal gag male sex ratio, several lines of evidence suggest that the current low male sex ratio (5% within the MPA and 0% in the Edges and Open area) is of concern. The mating function (relationship between sex ratio and fertilization success) plays an important role in the productivity of protogynous species (fish that begin life as females and transition to males) but is poorly understood.
Males displayed low milt (sperm) reserves during the spawning season which is a pattern associated with pair spawners. Although male spawning frequencies are unknown, given the low milt reserve gag displayed, this seems unlikely to be accomplished.
If the duration of gag sex change (i.e. the time it takes to become a functional male after receiving the cue to change sex) is similar to that of rock hind or black sea bass, approximately 2 months, then if female gag do not receive their sex change cue by December or January, which is when the females form pre-spawning aggregations, they will not be able to contribute as males in the upcoming spawning season, February through April. However, further research is needed to fully understand the proportion of fish transitioning prior to arriving at the spawning grounds.
Males had a larger average TL in the MPA compared to other areas, and the size and age of the transitional sampled in the MPA (14 years and 1107 mm/43.6 inches) was considerably larger and older than observed in the seasonally closed area (6 years old and 845 mm/33.3 inches). Our results of males and transitional smaller than 800 mm indicates there is not a minimum size threshold for a gag to change sex.
We propose a new conceptual model for gag sex change : Presumably, the largest, most aggressive females in a pre-spawning aggregation will transition. In gag grouper, the spatial distribution of their life cycle, their gender system, and their mating strategy impacts sex change, male recruitment, and the spatio-temporal level of fishing mortality they can sustain.
The very low levels of males seen in this study suggests that all eggs may not get fertilized, decreasing the stocks' productivity. The four sources of gag biological samples: (1) 3-year targeted study (blue, 37.5%), (2) FIM (orange, 21%), (3) FDM (gray, 37.9%) and (4) Ed Walker a collaborative fisherman (yellow, 3.5%).
The model shows pelagic gag larvae drift inshore and settle out in estuaries seagrass beds as nursery habitat where they continue to grow into juveniles from 5-7 months old and then move to nearshore hard bottom (in about 22 meters depth) as immature females, typically between 1-4 years old). As female gag mature, they begin to move offshore (in depths ranging from 15 to 121 meters) and form pre-spawning aggregations from November to February and most females migrate further offshore to the shelf in depths greater than 50 meters during spawning season (February-March) where males are thought to remain all year.
Green circles denote actively spawning females and the 10, 30, and 50 m depth contours are noted. Depth of female gag at capture by reproductive phase from fishery independent sampling (i.e. 3 year study and survey).