Abstract:

Aquaculture has become important for the economy of Thailand, especially the culture of the tiger shrimp (Penaeus monodon). In addition, there are other important cultured species, those are seabass (Lates calcarifer), grouper (Epinephelus coiaides), mullet (Liza subviridis), and banana shrimp (P. merguiensis). In order to meet the expanding needs of aquaculture, larviculture of these species has also been practiced in Thailand. Actually, the broodstocks of cultured species spawn naturally in captivity. Success in larval rearing has been achieved as a result of experience and management. Rearing of larvae is generally done in concrete tanks. Water quality management in larval tanks including the foods used in rearing, are the main factors affecting the success of this activity. Since excess food left in the tank causes both direct and indirect notorious losses in larviculture, the use of live food in shrimp culture can contribute to water quality and prevent the occurrence of diseases. Several species of phytoplanktons and zooplanktons including Chlorella, Chaetoceros, Skeletonema, Brachionus, Artemia and Moina are used in larval feeding. Larvae are generally fed with these live food at least for two weeks or even longer, e.g., for nearly two months in rearing grouper larvae. Enrichment of food organisms has been found to be essential just for some species, e.g., n-3HUFA for grouper larvae. In Thailand, plankton organisms grow fast most of the time. For example, Skeletonema needs less than 24 h to reach the peak of production, Brachionus can reach maturity within 12 h and increases 5-7 times d(- 1), whereas Moina reaches the mature stage within 24 h and increases 6-8 times/2-3 days. The production of these microorganisms could, thus, be profitably used for the larviculture.
(Natl. Inst. Coastal Aquaculture, Kao Sean Soi 1, Muang Dist., Songkhla 90000, Thailand)
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