By Sih-Yang Sim, Hassanai Kongkeo, and Mike Rimmer
1: Network of Aquaculture Centre in Asia-Pacific, Bangkok, Thailand.
2: Northern Fisheries Centre, Department of Primary Industries and Fisheries, Queensland, Australia.
Thailand’s success in breeding grouper species dates back to 1984-85 when the Phuket Coastal Fisheries Research and Development Center (Phuket CFRDC) and Satul Coastal Fisheries Research and Development Center succeeded in breeding Epinephelus tauvina
(possibly misidentified E. coioides
)[1,2]. The Phuket CFRDC also achieved the first successful grouper larval rearing during September 1984 to February 1985, when some 130,000 fry aged 45 days were produced.Juvenile coral trout (P. leopardus) produced at Trad CAS.
In October 1998, the National Institute of Coastal Aquaculture (NICA) based in Songkhla successfully produced giant grouper Epinephelus lanceolatus
by artificial propagation, but the survival rate was very low. In September 1999, NICA had another success in giant grouper breeding using preserved milt to fertilise freshly stripped eggs. Since that time, work at NICA has focused on shrimp aquaculture, while other coastal research stations in Thailand have continued to develop marine finfish aquaculture.
In 2002 the Krabi Coastal Fisheries Research and Development Centre (Krabi CFRDC), reported its first success in breeding and larviculture of tiger grouper Epinephelus fuscoguttatus
with a survival rate of 2% to 70 day-old juveniles. The Krabi centre has also succeeded in producing E. coioides
fingerlings for some years and now provides 100,000 – 200,000 fingerlings per year to Thai farmers. With the recent worldwide interest in ornamental fish, thanks to the film ‘Finding Nemo’, it is notable that Krabi centre has been able to produce seven varieties of clownfish (anemone fish) native to Thailand.Larviculture area at Krabi CFRDC.
After several trials in October 2003 the Trad Coastal Aquaculture Station (Trad CAS) in eastern Thailand successfully managed to produce its first batch of coral trout Plectropomus leopardus
fingerlings, which it has been consistently producing in small numbers ever since. As of 16 June 2005 there were some 12,000 coral trout larvae at 31 days of age. Trad CAS also holds broodstock of P. maculatus
(island or bar-cheek trout) but these have not yet spawned.
Mr. Thawat Sriveerachai, Chief of Trad CAS, said the key factor for success of coral trout breeding in Trad is water quality management. As Trad is subject to heavy rainfall throughout the year, it is important to protect the water quality in broodstock tanks from heavy variation, particularly in salinity. Trad station utilises recirculation systems and biological water treatment for coral trout broodstock, as well as other species. The recirculation system is a combination of traditional biological filtration plus bioremediation using shrimp, mollusks, sea urchins, swimming crabs and fish. The water in the broodstock tanks is changed only once per year. One inch coral trout (P. leopardus) fingerling in larval rearing tanks, Trad CAS.
The recirculation systems used at the Trad centre are low cost and relatively robust. In contrast, many of the more sophisticated recirculation systems available in the market today may not suitable for marine finfish species, are expensive, costly to maintain and problematic.
Trad CAS researchers have noticed that larval quality and survival is improved by enhancing the fatty acid composition of the live feeds used in larval rearing. Larvae fed nutritionally enhanced live feeds are usually of better quality and do not show the same ‘shock’ behaviour seen in larvae fed traditional live feeds.
In 2005, the Rayong Coastal Fisheries Research and Development Center (Rayong CFRDC) made a breakthrough in mouse grouper Cromileptes altivelis
larval rearing. The center uses the a simple recirculation system similar to Trad CAS for their broodstock holding facilities. The broodstock tanks are rather small at 3´5´1.2 m. Although mouse grouper broodstock successfully spawn in these tanks, egg production is low, which limits fingerling production.Mouse grouper fingerlings produced at Rayong CFRDC.
Rayong CFRDC also operates a large broodstock holding cage facility at nearby Koh Samet. This facility holds broodstock of several grouper species including P. maculatus
, E. fuscoguttatus
, E. lanceolatus
, E. coioides
, mangrove snapper Lutjanus argentimaculatus
and cobia Rachycentron canadum
. Like Trad, Rayong have not been able to spawn their P. maculatus
broodstock, despite attempts at hormonal induction of spawning.
There is considerable interest amongst the private sector in Thailand in developing marine finfish hatcheries. There is already considerable production of seabass Lates calcarifer
in Thai hatcheries, and many are keen to diversify their production to higher-value species such as groupers. A major constraint to diversification amongst private hatcheries is access to eggs and larvae. Many are now working with the government centers and stations so that when fertilized eggs are available in government facilities, they can obtain them for grouper larviculture trials. The government also provides training and technical support on grouper hatchery technology to the private sector.Marine finfish broodstock facilities of Rayong CFRDC near Koh Samet.Acknowledgments
We thank the following experts for their hospitality and provision of information for this article.
* Dr. Renu Yashiro, Director of Rayong Coastal Fisheries Research and Development Center, Department of Fisheries Thailand.
* Mr. Paiboon Bunliptanon, Director of Krabi Coastal Fisheries Research and Development Centre, Department of Fisheries Thailand.
* Mr. Thawat Sriveerachai, Chief of Trad Coastal Aquaculture Station, Department of Fisheries Thailand.
* Mr. Ekapol Wanagosoom, Partner and Manager of Aqua-Larval Farm, ThailandReferences
1. Ratanchote, A. and Puckdee Kiti, 1987. Study on propagation and nursing grouper, Epinephelus tauvina larvae. Review of the research on grouper culture conference, 23-25 February 1987 at NICA, 93-109.
2. Julavitayanukul, P., Putinowarat, Ch. And Suteemechaikul, N. 1987. Study on breeding of grouper, Epinephelus tauvina. Review of the research on grouper culture conference, 23-25 February 1987 at NICA, 74-81.
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4. Grouper News Issue No. 4
5. Asia-Pacific Marine Finfish Aquaculture Network Magazine No 3
6. Saving Thailand’s Ornamental Fish
7. Thailand Success in Culture of Coral Trout