Grouper Culture In RAS: The Introduction & Rule No.1

I saw a lot of interest on Re-circulating Aquaculture System shown by some visitors to this blog. My posting Introduction Of Recirculating Aquaculture System For Grouper Farming In Malaysia seem to get the most hits from the readers. In that posting, I did mentioned my wish to give my observations on the RAS that I manage to see in this country. I hope to be able to do so sometimes later. For now, let share the information on the system.

My initial exposure to RAS was way back to early 1990s when some grouper farmers in East Coast States of Peninsular Malaysia used to face high fish  mortality due to heavy rainfall during monsoon season resulting in heavy losses to them. I must say, it was too early to think about RAS during that period of time when even cage culture system was considered the most "modern" technology of the day. Later on, I get involve in cage culture of grouper fishes, only to confirm how inconsistent environmental factors will greatly affect the production as well reduce the management efficiency to the lower level with a lot of uncertainty and out of control conditions. It may frustrate even good and dedicated managers.


Abalone farming using RAS.
 Photo: Mahmud Ismail

I still remember a simple book but with very informative content published by INFOFISH with the title Recirculating Aquaculture Systems which I seriously consider as my text book during that time and remain relevant until today. (You may purchase this book on line now from INFOFISH Publication). Since then, I have seen many RAS farms in operation in many parts of the world, some in fully automatic system complete with additional support systems while others just basic RAS and some called their system as semi RAS.

High density turbot farming using RAS

One of the system that I want to mention here is an eel farm in Denmark which I visited way back in 2002 that have a production line from hatchery to finish products. The farm is using a fully automatic RAS with very minimum workers can be seen around but the fish seem to be being properly being taken care at every minutes during the farming period. In each tanks the water parameters were monitored automatically using probe sensors and reported to the control room in real time. There is no one at the control room either. Should anything odd taken place, the system will trigger the manager's and supervisor's mobile phone. To add to the sophisticatedness of the system, they are using green energy, by using wind turbine generator to supply the energy to their farm!

Another system that I always remember when RAS issue arise is a farm in Spain which I visited by the invitation from a friend from Tromso University, Norway. The farm always remind me of Stadium Melawati in Shah Alam Selangor because partly, that's how it look like. The farm contain circular tanks at various level. During my visit, they were farming turbot with capacity around 500 mt per year. They were using photo stimulant to enhance the growth of the fishes, play with gravity forces to reduce the pumping costs and the  fish physiology to do natural grading of the stock.

Mouse Grouper could be a right species for
RAS system.

Since introduction of RAS in 1970s, so much progress has taken place in this technology. Due to global pressure in marine capture fisheries and environmental problem in pan and cage cultures this system gaining popularity in many parts of the world. In the book, Urban Aquaculture (Cabi) some writers considered RAS could be the answer to the need for environmentally sustainable production of marine farmed organisms. However, since the initial and operating costs in RAS are higher as compared to pond, cage or pan cultures, anyone who want to invest in RAS must seriously consider the kind of species they wish to culture in order to achieve economic return on the investment. Generally speaking, we should go for higher price species if we are using RAS. Nevertheless, economic of scales in slightly lower priced species could also bring a positive results.

I always consider some grouper species are economically viable to be cultured using RAS. So, our first rule of thumb in choosing either to use or not to use RAS is the economic viability based on the price of the chosen species. 

Genetically Improved Farmed Groupers (GIFG)

There always some inspiration when I look at salmon industry. The industry growing in a very focus way to improve its productivity, efficiency and reducing the effect of potential problems. a lot efforts has been done to perfect the industry in various aspects. One of it is the genetic improvement of the farmed salmon strains. Recent report by FishUpdate  dated January 31, 2011 mentioned on the progress of study in Infectious Pancreatic Necrosis (IPN) virus resistance gene in salmon. IPN virus is  a major killer for commercial salmon farming especially for young fishes all over the world.

The researchers from University of Edinburgh, Institute of Aquaculture at University of Stirling and geneticist from Landcatch Natural Selection Limited (LNS) in United Kingdom manage to find this gene. In 2008, they published the evidence of an IPN resistance gene which is beneficial to prevent death of salmon from IPN. For the first time in aquaculture, LNS used marker assisted selection, an advance form of selective breeding, to improve resistance to IPN in their commercial strains. Further study now going on to find the precise location of the gene in the salmon genome and to identify additional genetic markers closer to the resistance gene. These Single Nucleotide Polymorphism (SNP) markers used to select the IPN most resistant fish for breeding. Their works surely shown a way for researchers in grouper industry to apply such leading-edge genetic and genomic technology in grouper's genetic selective breeding to help farmers to get a better strain for fast growing, disease resistant and highly demanded grouper fishes.



Hybrid between female tiger grouper and
male giant grouper.

 So far, not much result of groupers genetic research available in this country or even from this region. However, I must pay my respect for the best work done by some researchers in cross breeding of Giant Grouper (E. lanceolatus ) and Tiger Grouper (E. fuscoguttatus). Although this finding was not based on the work at gene level, I would say it is seriously a good achievement and should deserve all the credits. The output of this hybridisation technique currently in high demand in the market, getting very good price and acceptance at the consumers level.

Tilapia nilotica: Original and modified to suit the
colour's preference of the oriental markets.
Photo: Mahmud Ismail 

Last few years, the tilapia farming got a boost from the introduction of Genetically Improved Farmed Tilapia (GIFT) which brought good results in term of growth rate and flesh recovery which helps thousands if not millions of farmers around the world. I love to see such development in grouper farming. Since we do have good example from other farmed species, the chances of duplicating such process to the grouper species seem to be very natural way of getting the fastest results, before more serious works take place. Off course the situation of tilapia culture seem to be more easier than groupers culture due to single species (Oreochromis niloticus) needed to look into in the case of GIFT.

Since early of this millennium, some researchers already emphasize the need for further research on genetic improvement for the grouper species. I flip through some papers presented in one workshop on grouper aquaculture back in 2002 ( you can download it free for your own leisure reading from Proceeding of Grouper Workshop) and found suggestion from one presenter that emphasize the need for genetic improvement of the cultured grouper species. In this region, I saw some works on genetic improvement for grouper have been carried out in neighboring country but actual result from the study still not yet being published.

Should we become one of the scientist studying the genetic improvement of the grouper species, what could be our priority to look into? Perhaps the fast growing gene in Mouse Grouper, low salinity tolerant gene in most of grouper species, VNN virus resistant gene or something like new hybrid between Giant Grouper with Coral Trout? As for me, most probably I will go for fast growing gene for Mouse Grouper and Coral Trout. Perhaps, I will produce another version of GIFT for these kind of groupers. Can we call it GIFG?

Softshell Crab and Grouper Investments.

Yesterday and today news from local business news paper Business Times attract so much of my attention. The news not directly involved with grouper species, but since it involve with a move by a public listed company which seriously considering to invest in aquaculture industry, a kind of news that always being waited for by those who are involved in this field in Malaysia.

The news today is about the plan of Texchem Food Sdn Bhd, a wholly-owned subsidiary of Texchem Resources Bhd (TRB), whom has started laboratory-scale trials and experiments in the hatchery process of the mud crab. Texchem Food, which has been engaged in the seafood business for over three decades, is positioning itself as the world's largest processor and exporter of soft-shell crabs with access to a consistent supply of crabs in the region over over 100 tonnes per month. Yesterday, the company have signed a memorandum of agreement with Universiti Sains Malaysia (USM) to jointly study and do pilot-scale trials at the university's Centre for Marine and Coastal Studies (CEMACS) in Muka Head, Penang.

I like what being mentioned by Chairman and Chief Executive Officer of TRB, Tan Sri Fumihiko Konishi, who is mindful of the sustainability of natural resources and always ahead of the times with business trends, has not missed a beat in anticipating how an increasing market demand of soft-shell crabs will eventually stress the crab fishery. Everyone in seafood industry surely will agree Tan Sri Fumihiko on that remarkable note. The grouper fisheries have seen such pressure on some of the grouper species in Malaysia and all over the world and As I did mentioned in my earlier postings, I strongly believe that aquaculture could be the answer of this issue, should it being managed in a sustainable manner. 

Ability to produce fry from cultured animals should be the priority  for all of us in aquaculture industry. Dependency on wild broodstock have limitation and still giving some pressure to the natural stocks although almost unavoidable at early stage  of aquaculture industry development for certain species. For that matter, I take my hat off for TRB effort in developing a local in-house hatchery expertise for soft-shell crabs which aimed at acquiring the capability to produce crablets for further development.

Although I have seen softshell crab farming and crablet hatching since end of 20th century, the growth of that particular activity does not grow fast enough in this country. However, I must say there are already players who are producing this product in a relatively  serious mode but not yet at an industrial level. I hope the new effort by this TRB will boost the softshell crab farming to a higher level in Malaysia.

Another point in this two days news is the cooperation with the local research intitution, in this case USM. The initiation by both parties surely can ensure the potentials of crab farming and softshell crab production go beyond normal crab farming and fattening project. So much knowledge should be acquired and so much technical know-how must be perfected to ensure crab farming and softshell crab production achieve a sustainable level and eco-friendly to nature. Hopefully, other species such as groupers will get the same kind of attention from other PLCs and research institutes to push the aquaculture and fisheries industry into a new frontier. For those who are interested in softshell crab production, I recommend this book, Soft-shelled crab production: Options and opportunities for your reading.

Research On Groupers.

I was reading again(and again) a simple report in January-February 2009 issue of Global Aquaculture Advocate on trials of advance low-salinity culture of Cobia, Pompano and other species. The report was on successful collaborative efforts between Agricultural Research Service (ARS) of the United States Department of Agriculture  and  Harbor Branch Oceanographic Institute of Florida Atlantic University to develop and improve technologies for rearing marine fish in low cost, energy-efficient, low salinity and recirculating aquaculture system for various species. The broad issues in the aquaculture industry were addressed in holistic and integrated approach by bringing in diverse researchers of multi disciplines to address the bottleneck of the industry. 

What attract my attention to this particular report was on how research organisations and multi discipline researchers of broad based skills were gathered to improve the aquaculture technologies in USA. I love that kind of arrangements for solving and improving the aquaculture technologies. Reading from the report, it covers multi aquaculture species such as Cobia, Pompano, Southern Flounder, Summer Flounder and hybrid between Striped Bass and Black Sea Bass. By having multiple species will require different skills and knowledge in the research team. The researches of multiple disciplines to improve multiple issues at one time are efforts which require good centralised command. The issues covered from eggs to market.

Farming Protocols

Stripping the eggs from matured broodstock
of Mouse Grouper C. altivelis

Among the achievements from the studies are the  protocols on predictable   spawning pattern throughout the year using hormone inducement for pompano as well as black seabass and  mass production of juveniles in RAS (re-circulating aquaculture system) for pompano which helps in better growth, survival  rate and shorter time for metamorphosis.  The study also successfully documented the fecundity, fertilization rates and hatching success during numerous spawning trials conducted over the last four years. The ongoing research was designed to determine the optimal broodstock sex ratios, photothermal regimes and environmental cues to achieve natural spawning on a year-round basis for pompano. Should you interested to know more about RAS, I will recommend you to read in detail about it in this book: Recirculating Aquaculture. The study of such environmental stimulants is very interesting and I believe can be use as a basic knowledge to be use for our grouper hatching technique. Although hormonal inducement are now a well known technique in fish breeding, I personally paying more attention to the environmental stimulants that can be manipulated to induce the natural spawning activities among the grouper species because I believe such stimulation that actually trigger the spawning behaviour of most of the fishes in thier wild natural habitat.

What trigger the spawning activities of grouper fishes in their natural habitat such as in coral
area of  Tun Sakaran Marine Park, Semporna, Sabah? Photo: Sim See Hong.

Feeding Regimes

Come back to that particular research, the team also manage to find the way to short cut the enrichment process of live feed from 12 hours to 3 hours which directly will reduce cost in preparing the better quality live feed. Cofeeding of artemia with microparticulate as soon as possible can coincide with metamorphosis at 16 to 18 DAH (days after hatching) plus the usage of certain attractant to increase growth and survival of early postmetamorphic larvae of pompano. Since the usage of live feed is one of my subject of interest (in reducing the fry production cost), I hope to be able to benefit from this study in my own trial production. Perhaps the usage of algae and certain macrophytes could be the answer in reducing the grouper seed production costs. If you interested in this subject, I would like to recommend you this book: Use of Algae and Aquatic Macrophytes As Feed In Small Scale Aquaculture for your reading (you can download it for free).

Nutrition

The particular researches manage to determine the protein level in the diet for their targeted species. Black seabass achieve optimal growth with 45% dietary protein and 10% lipid. Pompano give optimal growth result at 48% protein (37% digestible protein) and 18% lipid in their diet. They found out that the diet for black seabass give the best result for the fish reared in decreasing salinity down to 10 ppt but give the different result to pompano when reared below 1 ppt. This indicate that the diet does not meet the pompano requirement at that salinity and the researchers now working to determine the amino acid requirements for pompano.

They found that fish meal diet give the best result for pompano and black seabass (and other carnivorous species) but still studying the best alternative to fishmeal from soy products, corn gluten meal, meat and bone meal, distiller's dried grain, poultry by-products (PBP) and blended meals in order to reduce the cost of feed in high and low salinity culturing regimes. The research manage to determine the amount of isolated soy protein that could replace the fishmeal for pompano and black seabass, which shown that 80% replacement of fishmeal is possible but the growth will significantly affected after 40% replacement.  They evaluated 5 poultry processing co-products for fish meal replacement and found that pompano grow well in 10 weeks farming period using 75% replaced fishmeal by poultry by products.

Well, we not exposed to such knowledge on effect of salinity to growth to grouper fishes although some observations shown the lower in salinity may help to reduce the cannibalism among the tiger grouper fishes. How ever about the fishmeal replacement, I was so pleased to read some reports from University Malaysia Sabah (UMS) on their success of developing diet for mouse and tiger groupers using poultry by-products which suppose to reduce the feed cost of grouper farming although we not yet see such feed in our market.

Engineering Aspects

In these aspects, the said research targeting to reduce the energy consumption to move the water in RAS. Pumping is the way of moving the water in RAS and normally using centrifugal pump. They found that using airlift pumps is a better alternative and lower in initial and operating costs. Airlift pumping system use the buoyancy of the entrained air bubbles to lift up and move the water.

Their study using 7.9 cubic meters tank with 1 meter depth shown that water moved by gravity down a PVC pipe to a 10 cm diameter airlift  riser pipe and lifted back into the tank using air from air blower. The submergence:lift ratio greater than 80% with the water velocity in the approach pipe was at least 61 cm/second while at the riser pipe the velocity was recorded at least 30.5 cm/second. They also found that the dynamic head increased with increasing water flow and  a greater freeboard in the tank increased the airlift need and off course, greater air flow was required to maintain a steady flow rate  in the tank. By placing the air injection lower in the riser pipe, a greater flow per unit was achieved. By applying such information, they manage to reduce 30% of their energy usage in a juvenile nursery. They evaluated airlift techniques for aeration either for the fish, filter and degassing needs in RAS. At the same time, they also evaluated total ammonia nitrogen (TAN) and solid waste removal, and water, energy and oxygen supplement in a low head system.

To most of us, RAS is still new and know-how on the subject still at a very infant stage. I do not know such engineering aspect being taught at our universities or not, either as part of their hydro-engineering  or aquaculture engineering subject. Hopefully, our graduates in fisheries from UPM, UMS, UMT and  UNISZA have equipped  themselves in such technology before they come out into fisheries / aquaculture sector.

Production

Using 3m diameter tanks in RAS system, (complete with  solid removal using swirl separators and rotating drum filter, with each system supplied with two floating biofilters equipped with automatic back washing controller, oxygen contactor, degassing column and ultraviolet sterilizer) the studies evaluated the grow out of hybrid striped bass, pompano and cobia from juveniles to marketable size. In 110 days trial, juvenile from 259g were stocked in 2 different densities at 5 ppt end up 632g and 570g respectively. Although food conversion ratio (FCR) were still relatively poor the results shown that pompano can be cultured in low salinity using RAS. In similar study, cobia with initial weight 322g  were reared  using RAS shown growth to 2.1kg in 119 days with excellent FCR, survival and 42% fillet yield. Both studies shown that both species can achieve a marketable size within a short period of time provided they were given right treatment and proper food.

I must say that I love that conclusion. To those who are still skeptical about RAS as a viable and commercial way in aquaculture investment, I sincerely suggest for them to look at all major seafood export countries such as Norway, Scotland, Denmark, Chile and study their way of doing their business. No doubt that you will find some still doing cage and pond culture, but at the same time most of the successful ventures done using RAS system.

Malaysian Groupers: Need For Concerted Efforts

My actual point in highlighting the studies done by ARS of USDOA and Harbor Branch Oceanic Institute of Florida Atlantic University is that our grouper farming industry also in the need for such broad based and multi disciplines researches which should be done in a very concerted efforts. I do not know who should lead the team nor who should become the member of the study team(s). However, from my personal communications with friends at various institutions that somehow related with aquaculture and fisheries activities, I can sincerely conclude that we do have expertise in that multi disciplines studies.

A simple RAS system for nursing of Seabass and Grouper juveniles in inland area of Bukit Beruntung,
Selangor which only cost the owner less than RM50,000 to set up. Photo: Mahmud Ismail

Maybe I can stress one simple point should such studies taken place. Please find the appropriate technology that suit us and easily adaptable to our farmers. Please don't show us the multi million Ringgit RAS system which non of us can afford to build or perhaps only few can afford to invest. I stress again the word appropriate, please find the APPROPRIATE technology for us. Another point, please, please, please and please make the finding available to all interested parties and stake holders. Please don't keep it as a secret to the researchers only, after a lot of public fund being used to fund such projects. Can we have such broad studies, multi disciplines, multi expertise and multi institutions in grouper farming in Malaysia taken place and answering  the real business need? My answer, always, Malaysia Boleh!

The Groupers and Aquaculture Investment.



Tiger Grouper Juveniles. Photo: Mahmud Ismail



Sometimes in May 2008, The Star Online reported the successful venture of  Global Hi-Q Bio-Tech (M) Sdn Bhd (GHQBT)  in indoor Tiger Grouper farming in Pulau Pangkor, Perak. I sincerely love to share such news for our aquaculture industry especially when it involved grouper species. The venture, which has at the time of reporting entered into Phase Two with  completion of its RM13mil nursery. I like what being mentioned by Johnson Chang, Managing Director of GHQBT, "The thing about Malaysia is that it is simply the perfect spot to breed this kind of fish” and he added "Malaysia’s suitability for the venture, was due to its geographical location and climate conditions". Yes, I fully agree with Johnson's statement. We enjoy such a stable climate for growing the grouper fishes and strategic location to the market places.

Pangkor Island where the said project being located:
Map Source: malsingmaps.com

The company also announced the usage of ecological re-circulating aquaculture system (ERAS), the technology which they claim as their secret to success behind indoor fish farming. While RAS is now getting popularity among our local fish farming community, I hope ERAS will enrich our aquaculture technology development in this country and hopefully there will be technological transfer to the local farmers.

I like the most of Johnson's further statements on the investment; "Global Hi-Q could secure a high net profit of between 44% and 52% and a stable return on investment of between 24% and 34%. With these figures, earnings can go up to RM500mil in just five years”. I hope our financial institutions will look up at his figures as an indicator how viable and bankable this industry can be should it be managed properly in all aspects especially with technology, expertise and good management practises.

Another point in the report that I love to share is the company intent to develop 100 local entrepreneurs in their technology. The same report said that  then Entrepreneur and Cooperative Development Minister Datuk Noh Omar, (now Agriculture and Agro-Based Industry Minister) during the launch of the nursery, gave his approval for 10 entrepreneurs to enter into the training programme under the company. “Those selected will be given RM300,000 loans each from MARA, with Global Hi-Q agreeing to stand as guarantor. The participants will get to manage their own fish farms which can produce about 20,000 metric tonnes of fish fry annually,” said Noh. I do hope the Minister will be able to look into the progress and extent more helps to those fish farmers since most of the activity is now under his own ministry. At the same time, perhaps the Minister can also consider the same arrangement to other proven local companies that might want to bring along their own vendor farmers in their successful ventures.

My Groupers, Norwegian Salmon and Icelandic Tilapia

When I read the report in the FISHupdate  dated January 2011 that Norwegian Seafood Export for the year 2010 increased from 44.8 billion kroner (RM23.2 billion) in 2009 to the new highest record in last 7 years of 53.8 billion kroners(RM27.8 billion) in 2010, I presumed that their aquaculture contribution could be just around 50% of it. But, I was wrong! Further details shown  that aquaculture contribution was 62% from their seafood export. Taking 62% of Norwegian seafood export in from aquaculture production, it is 1.674 million tons of production and 33.41 billion kroners (RM17.24 billion). Their seafood export were 2.7 million tons in 2010, an increase of 93 thousand tons from previous year. The same report indicated that their export value of salmon and trout increased by 29%, with France and Russia was their largest markets while China (including Hong Kong) was the fastest growing market in 2010. All those figures really stimulate my mind for our future development in fishing and aquacultre industry.

Atlantic Salmon. Picture: Wikipedia



Another report also in FISHupdate published on November3, 2010 said that Iceland plan to produce 10,000 tons of aquaculture production within next few years. There are currently around 45 registered fish farms in Iceland, with salmon rearing and mussel farms taking on a new importance. Fish farmers are also experimenting with high value species such as turbot and cod. The very same report also said that Iceland will start their TILAPIA farming in Flúdir. They think that tilapia breeding offer extensive opportunities and working with their grain farmers on producing fodder for the fish.

Tilapia nilotica harvested from the pond in Nile Delta area. Photo: Mahmud Ismail

I always want to compare our production with those giants in aquaculture or fisheries industry like Iceland, Norway, Denmark, Peru and Chile although sometime, I also take Taiwan to be my yardstick for measuring our achievement. There are reasons why I choose to look at those countries and not our neighbouring countries like Thailand, Indonesia or China even though these countries are main seafood producers too. One of the factor that I think we are similar to those fisheries giants countries is minimum supply of manpower into fishing and aquaculture industries.

Lack of manpower in those countries have became their driving forces to modernise their industry accordingly, so they decide to use modern equipments and technology to ensure their productivity will remain competitive with other countries. In our case, we decide to import immigrant labors to fulfill our shortage, so we assume we are as competitive as our neighbouring countries in term of our productiveness. For so long, that was the picture of our fishing and aquaculture industries. In the case of main seafood producing countries as mentioned above, the technology will remain with them forever and will be improved according to time and needs.

In our case, once the labor immigrants return to their countries, we will still remain as we were before and in the need to look for cheap labourers again. Perhaps, we should re-strategize our whole fishing industry all over again. The new 21st century that we are living now will not ensure that we get the cheap labours from neighbouring countries anymore. These neighbouring countries themselves now moving forward for modernization of their fishing industry, perhaps using our ex-man powers.

Live fish market in Hong Kong. Photo: Mahmud Ismail.

Our fisheries statistics will soon be published, I presumed, based on previous years experiences. I strongly believe that our export value too will show some improvement, be in value and quantity, both from capture or aquaculture productions . I hope the export of live groupers  too will show the same trend, taking notes of intensive private sector investments in the fisheries industry reported lately in all states. While waiting for the official figures to be published, I presume Sabah, Johor, Selangor, Perak and Pulau Pinang will remain the main exporting grouper fishes in Malaysia while Terengganu and Kelantan will be following soon into the list.

Malaysia: Grouper Production 2005-2009.

21st century should make us well informed fish farmers especially on latest technological research and developments in fishing and aquaculture industries. I wish to see our farmers to get such information from various sources available now. For serious readings in aquaculture development and new technology, I strongly recommend  Global Aquaculture Advocate and Aquaculture Asia to get into latest information on who and what in this industry.

I also hope we will equip ourselves with the marketing information for our targeted markets of your products. Should Asian countries is your prospect market, the The 2009 Import and Export Market for Live Fish in Asia report should be your base information. In my case, I single out my attention into a niche China markets, where the information about it easily available in The 2009 Import and Export Market for Live Fish in China. While most of grouper farmers in this country are eyeing for the same market direction as me, I think another market perhaps can be explore, i.e. South Korea (The 2009 Import and Export Market for Live Fish in South Korea) and Japan.

We shall wait for our statistics to come out soon to see either our grouper production increase in the quantity and value as we hope too. If our production was not as high as in the case of Norwegian seafood export, we might want to look into our own targets, and keep asking what needed to be done to make ourselves at par with those giants in fishing and aquaculture ondustries. Maybe we want to look into our tilapia production too, so that we can be make a comparision between our production with Icelandic Tilapia. Unfortunately, our latest published statistic on the Ministry Of Agriculture website was only up to June 2009 while Department of Fisheries website's was still on 2008 figures.

Orange Spotted Grouper, Kerapu Pinang, Epinephelus coioides

Orange Spotted Grouper. Photo Credit: Randall J.E.

Locally, this species were called with many names as in case of other grouper fishes. Kerapu Pinang, Kerapu Balong, Kerapu Rintek and other names.  When I start to get involved with this species back in 1997, the farmers call this fish as Kerapu Pakpanang, probably because the fry of this species were imported from an area of the same name in the neighbouring country. Back then, Orange Spotted Grouper (OSG) was among the important species of groupers that were cultured in this country before the currently cultured species start to gain their popularity among the farmers. However, this species are still being cultured in this country with intended local and export market.

OSG always associated with the coral reef ecology but sometimes also can be found in the brackish water from the depth of 1 meter to 100 meters. They were also found in the brackish estuaries ecosystem especially for the juveniles. This species can be found in the seas of  37°N to 34°S and 28°E  to 180°E which include Indian Ocean, Red Sea, Andaman Sea, Malacca Straits, South China Sea, China Sea and Western Pacific Ocean. There were reports of catches of this fish in the Mediterranean Sea.

Mangrove area at the estuary where OSG can also be found. Photo: Mahmud Ismail

This species fed on fishes, squids and crustaceans. In our waters, the juveniles were found weeks after rainy season were over or weeks after heavy downpour suggesting that the spawning taken place immediately after rainy seasons is over. Some scientists predict that there are spawning aggregasion behaviour for mating time and their eggs floating below the surface level. They were pelagic during larval and juvenile stages. Some other suggest eggs, larval and juveniles were pelagic due to existing of all levels pelagically.


Price of OSG quite stable for the last 3 years. Source: Fish Marketing Organisation HK.



 In the last 3 years, this species enjoyed relatively stable price between HK$105/Catty to HK$131/Catty and the last one week from the date of this posting, this fish were priced between HK$130/ Catty to HK$140/Catty. The price of OSG was much below then our other popular species such as GG, TG, MG and Coral Trout, but always higher than GGG. In the local live fish markets, the ex-farm price were  species still remain good especially for live seafood markets. For me, should the demand for OSG getting bigger and the price is better, or we able to reduce the production costs (with better FCR, genetically improved fry),  this species is the choice for our local aquaculture industry. The researchers from this region has shown their innovation when they manage to mass produce the hybrid of TG and GG in the last few years. Why not do something on this species too? Perhaps an hybrid between OSG with GG?