Groupers and Hinds
Hind Family
Chocolate Hind
Chocolate Hind is very adaptive to our waters and is very commonly caught along shores or offshore. They can dwell in waters as shallow as 1 ft to as deep as 100 ft or even more. They are very easy to catch because they tend to take the bait whole without hesitation and will even take big pieces of bait. However, they typically don't grow very big and their meat don't quite match up to other groupers like the orange-spotted grouper.
They aren't choosy with the type or size of baits. Like other groupers, they have the tendency to dash into rocks after they take your bait. However, they're reaction isn't as fast as other species. They don't fight very well and resists very little; only resistant you will probably feel is the water resistant from its wide opened mouth as you retrieve it back with the fish spinning.
The chocolate hind is a protogynous hermaphrodite, they undergo a sex change from females to males.
In Hong Kong it has increased in commercial importance as a result of the decline of larger-bodied species of grouper and the chocolate hind is now one of the more important species in the Hong Kong fish market
Blue-lined Hind
The Blue Line Grouper is a common favorite among fish only aquarists. Often willing to accept not only a captive diet, but to learn to eat from the hand of the aquarist is endearing.
Groupers are ambush predators and will spend much of their time hiding and watching for easy prey. Groupers should be housed in large aquariums with good filtration.
Caution should be considered when adding this animal to a community tank as it will eat any fish or crustacean that may fit in it’s mouth.
Cost anywhere from 50SGD to 150SGD in the aquarium trade (USA)
Groupers will fight with any fish they don’t like and require a large tank to help curve their aggression.
Never keep two of the same groupers together in a tank. These fish, while often calm towards other species, will not stand for another of their kind in a small environment. Unless your tank is absolutely massive do not try and own two of a kind.
Peacock Hind
A hardy aquarium fish for those who have a large marine aquarium. Its large size combined with its aggressive nature means it is best housed either alone or with other large aggressive fish such as lionfish, and moray eels. As a predator it will eat any smaller aquarium inhabitants such as damselfish.
Known in Hawaii as roi, the state introduced the species in the 1950s to enhance local fisheries. Hawaii's Division of Aquatic Resources (DAR) finds that roi have become the reefs' dominant predator. The Roi population there has increased 15 fold since the 1980s. From 1999 to 2005 there was a 23% increase in their population. Their biomass is now greater than that of all other reef fish predators combined.
Prized as delicious eating in other Pacific regions, in Hawaii's waters roi may contain the ciguatera toxin, which builds up in humans and causes serious illness. A study published in 2007 found that 18% of Roi sampled from Oahu and Hawaii islands had toxins above levels safe for consumption. Due to high variability of toxin levels between individuals in the same area, toxicity cannot be predicted based on location. There is a weak correlation between the length of Roi and their toxicity, however, due to high variability, this is not a reliable predictor of toxicity.[5] There is currently no commercially available testing kit. Because of the toxicity issues, Roi does not have a functional fishery, with just an average of $1000 per year in sales
Grouper Family
Orange Spotted Grouper
All Orange-spotted Groupers are born female. However, at around 4 years old, if there are not enough males in the local population; some females turn into males.
Common and expensive, sold fresh and kept alive at restaurants in Asian countries (e.g. Hong Kong, Taiwan, Singapore)
A popular fish for aquaculture, (Fish farms)
It is among the common fishes eaten in Singapore. Here, these fishes are sometimes reared in floating cages from fingerlings (young fishes) that are imported from neighbouring countries, until they reach marketable size.
The main issues constraining the further development of orange spotted grouper farming include:
This species grow more slowly on formulated feeds with high protein levels than many carnivorous farmed species.
Although grouper culture is widespread in Asia and the Pacific, its continued development is constrained by the limited availability of fingerlings. Most economies, with the exception of China Taiwan P.C., rely almost totally on wild-caught fry and fingerlings for stocking.
There is a lack of appropriate techniques for efficient grouper culture to marketable sizes. A major production constraint is heavy mortality of groupers during the collection and culture phases due to handling stress and diseases. High mortality rates occur in the early larval stages and larval cannibalism is rampant. Farmed fish are also often prone to diseases (especially viral diseases and parasitic infestations).
Used during production mainly to prevent and treat bacterial disease, antibiotics are leading to the development of antibiotic-resistant bacteria that are pathogenic to humans. The development of antibiotic resistance by pathogenic bacteria is considered to be one of the most serious risks to human health at the global level. Many countries around the world have introduced, changed or tightened national regulations on the use of antibiotics, in general and within the aquaculture sector.
This grouper is often confused with the Malabar grouper because the pattern on their body is very similar. If you look closely at the dots on their body, Malabar Groupers have black spots while Orange-spotted Groupers are orange.
Cloudy Grouper
Inhabits areas with muddy or silty-sand bottoms.
One of the most remarkable characteristics of this and other grouper species is that every fish begins life as a female before turning into a male once it has attained a certain age and size. This gender reversal most frequently occurs at around 12 years old.
Cloudy 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.
Malabar Grouper
This grouper in common in rocky shorelines throughout the island. Its habitat is less widespread than the orange-spotted grouper, prefers shallow reefs and rocky banks such as breakwaters. They can adapt well to brackish water as well.
Groupers usually have a hiding place, usually among rocks to ambush prey. They will snipe the prey within range and will quickly dash back into its hiding place. Anglers must be anticipate for a grouper strike when fishing in rocky area. Response to a grouper hit must be swift and a little harsh initially to pull the grouper away from its hiding spot. If the grouper is given a chance to dive back into the rocks, it will erect its gill covers and use them to anchor itself firmly between rocks.
Their mouths and gills form a powerful sucking system that sucks their prey in from a distance. They also use their mouths to dig into sand to form their shelters under big rocks, jetting it out through their gills.
Groupers are intensely targeted by spearfishing sports divers
Honeycomb Grouper
In 1956 they were introduced to Hawaii as a possible new food source.
The genus Epinephelus has the ability to change sexes, more specifically they are protogynous hermaphrodites what means females can turn into males at one point in their life. This sex change usually happens in the non breeding season and can be caused by social stimuli, age, growth, and body size. Yet, the initial trigger for the sex change remains unknown
It is among the common fishes eaten in Singapore. Here, these fishes are sometimes reared in floating cages from fingerlings (young fishes) that are imported from neighbouring countries, until they reach marketable size.
The honeycomb patterns helps them to blend into coral reefs and rocky structures
Coral Trout
Coral trout is not a trout at all. These fish are actually a member of the Grouper and Cod family possessing a large mouth and sharp conical teeth. When Europeans settled in Asia, they named many fish after those they resembled at home. Coral trout species have spots along their back like brown and rainbow trout
Coral and coronation trout species are prized for their striking appearance. In Asia they are in demand for the live reef fish and aquarium trade. Their delicate flesh makes excellent eating.
Like all coral trout, barcheek coral trout are protogynous hermaphrodites. This means they begin life as females, sexually maturing at about two years old, then changing into males permanently when between three and seven years old. They will breed as females at least once before becoming males. Female barcheek over six years old are rare. It is thought that 50 per cent of females sexually mature at around 18 months old and 30cm fork length . Although males and females can be found at most lengths, generally small fish will be females and large fish males.
They tend to be solitary and normally patrol their home reefs, but may travel a short distance away to spawn. Barcheek are more vulnerable to overfishing and localised depletion than the other grouper species, owing to living closer inshore and thus being relatively easily reached by line and spear fishers.
Studies of the common coral trout suggest they seldom move from one reef system to another, usually returning to the reefs where they were spawned after any movements. This settled non-migratory behaviour means fisheries managers need to guard against individual reefs being overfished.
Coral trout have very energetic breeding behaviour. Normally solitary fish, they gather in dense groups (called aggregations) of between 60 and 130 fish to spawn during a 30 to 40 minute period at sunset
Coral trout have very energetic breeding behaviour. Normally solitary fish, they gather in dense groups (called aggregations) of between 60 and 130 fish to spawn during a 30 to 40 minute period at sunset (a coral trout orgy)
Coral trout caught commercially fetch a high price on both overseas and local fish markets.
.As fishermen like to target the largest fish, in the case of coral trout this means males are more likely to be removed from the population than females.
The difference in colour between individuals is a camouflage strategy with pink more suited to the duller light conditions of deeper waters. In the absence of the red wave lengths of light at depth the pink colour makes the fish appear olive brown in colour which is ideal for hiding in the shadows
An eight-storey fish farm that is currently being developed by the Apollo Aquaculture Group (Singapore) will involve the production of hybrid grouper and coral trout across three storeys
Hybrid Groupers
As far back as 1996 the University of Malaysia produced a giant grouper/tiger grouper hybrid, dubbed the Sabah Grouper specifically for live reef fish food markets in Hong Kong
For grow-out operations, producers report that hybrid groupers have generated more total farm income than any other species they farm. This trend held for farms across all income levels.
Hybrid grouper is produced by mixing milt from giant groupers (E lanceolatus) with eggs from tiger groupers (E fuscoguttatus). The hybridisation allows producers to capitalise on the favourable growth rate of giant groupers while also maintaining high survival rates associated with tiger groupers. The new species of fish has caught on with Singapore consumers. Sale prices for the fish are strong and demand remains consistent despite its recent introduction in the market.
These hybrid groupers are an invasive species that could potentially upset the ecological balance in our waters. In particular, the groupers may compete for food and territory with other domestic species. Local fishes could even be eaten by these hybrid groupers, according to folks from Marine Stewards.
The environmental conservation group also encouraged people who need to release fishes – such as for religious purposes – to approach them directly. This way, they could link them up with researchers who would be able to advise them on the appropriate types of fishes and where to release them. In doing this, it could even help restock our local fish population. They concluded that acting responsibly in this manner can be a win-win situation for all, including for our marine wildlife.
In fact, NParks has also constantly reminded the public not to release animals into the wild as it might disrupt natural habitats and the species that live there.
This is especially so for marine animals as aquatic ecosystems are very complex and sensitive. In serious cases, it might even affect the quality of our waters.
The current thinking is that hybrids are infertile, but there are examples of the devastation hatchery-bred species can inflict on wild stocks
Grouper can sell for well over US$100 (£59) a kilo, with very large or rare specimens selling for much more.
The market is huge. In Hong Kong alone, an estimated 3.6 million grouper are consumed each year. Demand has led to rampant overfishing across South East Asia’s Coral Triangle, a million square kilometre bioregion that’s home to more marine species than anywhere else on earth. Fishermen often use cyanide to stun grouper, destroying coral reefs in the process. According to a recent University of Hong Kong study, one in ten grouper species face extinction if current trends aren’t arrested.
In theory, advanced aquaculture techniques offer a way of fulfilling demand while reducing the pressure on wild populations. In reality, aquaculture has simply added a new market, with additional sealife being taken from the ocean to feed farmed fish in Malaysia, China and Taiwan.
Grouper are hermaphrodites – or monandric protogynous hermaphrodites to give them their full title. Early in their growth cycle they are females, but in adulthood they can change into males. No one knows the precise trigger for this transformation, though size, age and environmental factors all play a part. Hybrid groupers in captivity are all female – but in the wild they could easily change sex, according to Wong. Which brings up the possibility of a sort of “X-Grouper” wreaking havoc with the food chain.
Grouper are nurtured first in hatcheries from cultivated eggs and then in coastal cages or factories. Hybridisation aims to achieve the holy trinity of rapid growth rates, resilience and superior taste.
The live reef fish for food trade is a notoriously under-regulated. It’s also highly lucrative, worth as much as US$1 billion annually. But consumption tends to follow a boom and bust cycle. Once the Sabah Grouper became readily available its per kilo value dropped dramatically and many farmers found themselves priced out of the market.
“Supply of hybrids is far outstripping demand,” says Dr. Muldoon. “A big question is, how will farmers dispose of hybrids they can’t sell?”
Groupers that farmers can’t sell (or are sick) will be sold in bulk to religious groups for mass release operations.
Sixbar Grouper
Generally found near Sandy bottom
Its six strips helps it to blend into the natural contours of the sandy bottom.