It is a protogynous hermaphrodite, meaning it begins life as a female and changes to a male as it matures. It is treatable in humans, but the concern is that ciguatoxin can move up the food chain via bio amplification and spread to other species.
But we have an imported grouper species all throughout the main Hawaiian islands called the ROI or peacockGrouper. This fish was imported to Hawaii in the 1950s from French Polynesia and since then has spread to almost all the Hawaiian coral reefs.
Where it occurs naturally in Tahiti it sells for up to $8 a pound and is a prize dish in the local restaurants. Even though this 20-inch long fish is now very common in Hawaiian waters and easy to catch it is not often eaten by the local community.
Then the ROI just gulps it down with its large mouth and series of hundreds of small bristle like teeth. If it contains ciguatera you would have some kind of mild stomach reaction within three to five hours according to the finding from the UH study.
Catching the ROI for food is a good sustainable food source that helps our coral reefs and maybe we can lower the populations to help our native fish species, but each person who chooses to eat them really needs to be cautious and not eat a large portion of the fish right way until you know it is safe. The ROI are extremely beautiful fish to look at, and they may or may not have white bands on their blue and brown smooth skin.
You can see the ROI in action in my video The Worlds Guide to Hawaiian Reef Fish up on my underwater educational web page at www.underwater2web.com and also follow my marine life identification series on my Instagram at terry.Villa. As can be seemed in the images they can also put light whitish vertical bars on the body which aids with camouflage and is used for territorial disputes and mating.
In research conducted on the Great Barrier Reef individuals of up to 40 years in age were found. They have the ability to lighten their coloration and will sometimes have white vertical bars down their body.
The two males approach each other from the front and then turn sideways at close to a right angle so that each can see the others body. They are found on the East coast of Africa from Durban in the south to the Red Sea, eastwards to the mid Pacific including most islands.
They are typically found on exposed reefs rather than in protected areas or estuaries. However, multiple cases of ciguatera poisoning occurred which were traced back to the PeacockGrouper.
Their main diet is small fishes and crustaceans, however given they are caught by fishermen on the hook this indicates that they will scavenge as well. They are ambush predators and feed in the early morning and late afternoon when their coloration gives them more camouflage.
Based on social and environmental cues some larger females will turn into males. Mating typically occurs around spring tides when there is more water movement.
With their bright coloration these fish are kept in large aquariums by some specialized collectors but because of their propensity to eat smaller fish great care has to be taken with their tank mates. If one dives in the Marine Park on Mafia Island there are noticeably far greater numbers of this species.
Groupers of the world (family Serranidae, subfamily Epinephrine). ROI or peacock grouper, were introduced into Hawaii in 1956 from Mo'area to add to the food source for Hawaiian fishermen.
ROI spend most of their time in deep caves and cracks in the reef where they prey on other fish like allowed, Memphis and Ala'hi. I also make movies for schools, government agencies and the public about our marine life and invasive species like ROI, ta'ape and to'Au.
I have observed several large ROI that seem to stay near the same caves, but they will move when the surf changes or you scare them away. In Canada Bay from the shore out to one mile I have done over 100 kayak scuba dives and I have speared over 80 ROI of which I sent to UH for testing.
This concentration of ROI vs native fish is very dangerous for the long term health of our reefs. Ten years ago at many spots on the north shore like Tunnels Reef, I have seen many of the native fish decline and the ROI spread.
Fishermen do not normally eat the ROI because they have been known to carry the ciguatera toxin, and they could make you very sick! The current test kit for ciguatera is not extremely accurate and cost a lot.
If UH could make a good test kit that cost little then fishermen could go back to catching and eating ROI. Free divers can target certain species without damaging the reef or marine life.
Some scientist claim that ROI take the place of Ulna as a top predator. If we spent more time and money studying Ulna, UK, Mile and other predators and develop additional plans to increase their populations, then we would be returning our reefs to a healthy state.
Using an invasive species to repair a damaged ecosystem rarely if every work! Roi could also carry bacteria that are not native to Hawaiian waters. I did an underwater movie about Kauai's free divers, and they are very good at what they do, and they understand the ocean and marine life quite well.
Rising sea levels, run off, improper building, polluted rivers and over use of certain reefs by tourist cause much more damage to our coastal ecosystem than fishermen do. As scientist, we need to work with fishermen, divers, surfers, hunters and other native people as they are “the eyes on the reef” we need to learn from and share with.
Synonyms and Other Names: Serra nus master Valentines in Cuvier & Valentines 1828, Cephalopods Gustavus (Bloch 1790); blue spotted grouper, peacock grouper, peacock rock cod, ROI Taxonomy: available through www.itis.govIdentification: Previous reports (e.g., Mailed 1984) refer to this species as Cephalopods Gustavus.
Small blue Bocelli ringed in black cover the body. Five to six pale vertical bars are often apparent posterior to the pectoral fins and a large white patch occurs on the breast.
Dorsal, anal and caudal fins generally with a narrow white band along their posterior margins. The blue spotted hind has a similar color pattern, with a reddish-brown background and blue Bocelli covering the body.
Similar species in Florida: Coney (Cephalopods vulva) has two black spots on lower lip and two black spots at base of canal fin. Grays by (C. orientates) has red spots on the body and a rounded caudal fin.
Red hind (Epimetheus Gustavus) has dark margins on rear dorsal, anal, and caudal fins. Native Range: This common and widely-distributed grouper ranges from the Red Sea to South Africa and east to French Polynesia and the Pitcairn Islands group, including northern Australia, Lord Howe Island and southern Japan (Heemskerk and Randall 1993; Carpenter and Nail 1999).
Early reports (from Valentines in 1828 and Quo & Gamma rd in 1824) listed the species from Hawaii ; however, these reports are considered erroneous (see Randall and Ben-Tuvia 1983; Randall and Heemskerk 1991; Muddy 2005). Non indigenous Occurrences : In Hawaii, 571 small individuals from Moore (Society Islands) were released off the islands of Oahu and Hawaii in 1956 (Randall 1987).
These fish became established in the Hawaiian Islands and entered the commercial and sport fisheries by the early 1970s (Randall and Alabama 1972). The species is present in the Kaloko-Honokohau National Historic Park (Ailment 1999).
In Florida, the peacock hind has been seen off Boca Raton in 2004 (T. Jackson, peers. ), Pompano Beach in 2005 (REEF 2008) and Key West in 2006 (T. Jackson, peers.
Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Cephalopods Argus are found here.
Ecology: This common grouper occurs on coral reefs over a depth range of 1-40 m, typically less than 10 m (Shrivel and Michelson 1989b; Heemskerk and Randall 1993). The species is territorial, and partitions its habitat into large (up to 2000 m 2) territories occupied by a male and up to 12 females and sub-territories, each inhabited by a single female (Shrivel and Michelson 1989b, 1991).
Like many groupers, the peacock hind is a protogynous hermaphrodite, and switches from a female to a male during its lifespan. Females reach sexual maturity at 1.2 years (20.0 cm TL).
Sex change, when females transition into functional males, occurs around 11.2 years (39.9 cm TL) (Stemmed et al. 2016). The species feeds primarily at night in Madagascar (Harmelin-Viven and Bourbon 1976), but feeds during the early morning and late afternoon in the Red Sea (Shrivel and Michelson 1989a,b).
The diet is composed mainly of fishes (generally over 80%), but also includes some invertebrates (Randall and Brock 1960; Harmelin-Viven and Bourbon 1976; Shrivel & Michelson 1989a). The peacock hind is able to consume surprisingly large prey items; one report documented that a 231 mm peacock hind consumed a 203 mm prey fish (Randall and Brock 1960).
The peacock hind is an important food-fish throughout the Indolent Pacific region; however, due to its carnivorous nature, it has been blamed for numerous cases of Ciguatera poisoning in both the native and introduced ranges (Randall 1987; Heemskerk and Randall 1993). A study in Hawaii by Dairying and Camera (2009), showed that 18.2% of C. Argus specimens collected contained ciguatoxin in concentrations potentially harmful to humans.
Means of Introduction: Intentionally stocked as a food/sport fish in Hawaii'i. Status: Established in Hawaii (Randall and Alabama 1972) as far north as Ni'IAU (Muddy 2005).
Impact of Introduction: In Hawaii'i this species has spread throughout the main islands and has become the dominant large-bodied predator on reefs. A diet study by Dairying et al. (2009) showed that 98% of the diet was composed of fish and that peacock hind consumed many kinds of fish.
Ciguatera in the introduced fish Cephalopods Argus (Serranidae) in Hawaii'i and implications for fishery management. Diet composition and prey selection of the introduced grouper species peacock hind (Cephalopods Argus) in Hawaii.
Courtship and spawning behavior of the pygmy grouper, Cephalopholisspiloparaea (Serranidae: Epinephrine), with notes on C. Argus and C. rode. Feeding behavior of some carnivorous fishes (Serranidae and Scorpaenidae) from Tulane (Madagascar).
A review of the groupers (Pisces: Serranidae: Epinephrine) of the Red Sea, with description of a new species of Cephalopods. Observations on the ecology of epinephrine and Jutland fishes of the Society Islands, with emphasis on food habits.
Revision of Indo-Pacific groupers (Performed: Serranidae: Epinephrine), with descriptions of five new species. Report on the introduction of serrated and Jutland fishes from French Polynesia to the Hawaiian Islands.
Exotic species sighting programs and volunteer database. Reproductive life history of the introduced peacock grouper Cephalopods Argus in Hawaii.
Food habits and prey selection of three species of groupers from the genus Cephalopods (Serranidae: Teleostean). Habitat partitioning between species of the genus Cephalopods (Pisces: Serranidae) across the fringing reef of the Gulf of Arab (Red Sea).
Territoriality and associated behavior in three species of the genus Cephalopods (Pisces: Serranidae) in the Gulf of Arab (Red Sea). Management of nonindigenous aquatic fish in the U.S. National Park System.
Paper presented at the 129th Annual Meeting of The American Fisheries Society, Charlotte, North Carolina, September 1, 1999 (unpublished manuscript). The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.
Anthony Ballad in Northeastern Hawaii Island on November 8, 2019. This particular specimen was black with small white spots and had a bluish tinted belly.
The Hawaiian grouper has a body which has a standard length that is 2.3 to 2.7 times its depth. It has an angular properly which has 3-4 enlarged serrations at its angle, with the lowest pointing downwards.
The upper margin of the gill cover is convex. The dorsal fin contains 11 spines and 14-15 soft rays while the anal fin has 3 spines and 9 soft rays.
The membranes between the dorsal fin spines are deeply notched. The adults are dark brown in overall color and are marked with 8 vertical series of faint white spots which are obscured by many extra pale spots and blotches which vary in size.
The fins of adults are largely plain and have a similar color to the body apart from a few pale spots along the base part of the dorsal fin. The Hawaiian grouper is a reversal species which is found on coral and rocky reefs at depths between 20 and 380 meters (66 and 1,247 ft).
The spawning season runs from February to June, peaking in March. The Hawaiian grouper is valued for having clear white flesh which has a delicate flavor.
It is regarded as a member of the “Deep 7” group of fish species which live in deep water, near the bottom, and are a valuable resource for fisheries in Hawaii, these species accounting for 50% of the total commercial catch in the State. IUCN Red List of Threatened Species.
Pacific Islands Fisheries Science Center Administrative Report H-08-06, 19 p, http://www.pifsc.noaa.gov Gilmore, Jerry G.; Ballad, Anthony: Malaya Charters Hilo LLC, Commercial fishing vessel “Jovan Lee” field work, Northeastern coast of Hawaii Island (12/2019-3/2020) Took a friend whipping on the south shore who hadn’t fished in more than 10 years.
The afternoon trades were blowing and the sky was overcast, which made our initial dip in the water feel a little shocking. The fish weren’t biting on the shallow reef, so we hop scotched our way to the outer edge where it dropped off into a 12 – 15 foot sandy channel.
The turtle eventually got tired of scaring us and bobbed back and forth in the open channel about 20 yes away. It immediately got hammered by what looked like black hummus, saddle wrasse, and dark and light colored pupils.
But when I hooked a finale, the black fish lunged for it and missed, wisely staying far away from the surface. My friend, still shaken by the turtle that was bobbing up and down making noises like an old man snoring, was captivated yet a bit uneasy watching the cycle of life struggle below.
More determined to see what this dark marauder was, I dropped the bait down again, felt the rat-ta-tat-tat of a finale and then a half second later the line was peeling off my reel. I strongly suspect the mystery fish was a ROI (peacock grouper) and that it nailed the finale and holed up tight in the reef.