EXPERT TOPIC
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SHRIMP GROUPER
GROUPER FARMING
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Learning from past mistakes and building a better future by Huey-Lang Yang, Research Professor, National Cheng Kung University, Taiwan
roupers are fish of several genera in the subfamily Epinephelinae of the family Serranidae. They are wild and spread globally in many warm water oceans, and can be quite large, such as the giant grouper (Epinephelus lanceolatus), which can commonly weigh up to 400kg. Unlike other commonly farmed fish, grouper is a demersal fish that usually does not swim continuously, thus, it is an efficient and suitable fish for culture.
Current key bottleneck and disease
The stable supply of fingerling has facilitated the grouper farming in the past twenty years and about 100,000 tonnes of grouper was produced in Taiwan, China and south Asia at 2013. However, high-density farming and repeated use of farming sites with non-responsible farming management has created drastic problems which has caused the industry to suffer many unsolvable problems in the past several years. One of the major constraints is the disease, many diseases have already occurred such as VNN (Viral Nervous Necrosis, disease caused by NNV) which infects the brain and nervous system at the
Farmed species
At least eleven species of grouper have been farmed and the fertilized eggs of the following ten species are commercially available in Taiwan, such as giant grouper: (E. lanceolatus), longtooth grouper (E. bruneus), coral trout (Plectropomus leopardus), red spotted grouper (E. akaara), orange spotted grouper (E. coioides), brown marbled grouper or tiger grouper (E. fuscoguttatus), Malabar grouper (E. malabaricus), camouflage grouper (E. polyphekadion), greasy grouper (E. tauvina), and polka dot grouper (Cromileptes altivelis). Two species, such as E. coioides and E.malabadicus, have been successfully induced spawning, but other species are still unstable, such as E. bruneus, E. lanceolatus and P. leopardus. The cultured fingerling has replaced the wild catch fingerling for most of the grouper farming. Grouper as a bottom fish is generally cultured in earthed ponds and shallow floating net cages in Southeast Asia. The current culture system is fragmented and separated into at least four stages: brood stock farm supplies the fertilized eggs; hatchery supplies hatched larvae, nursery provides various size fingerlings to grow out farm. All the stages have their own knowhow-based farmer’s experiences. 36 | March 2017 - International Aquafeed