Acknowledgements
This research is supported by Thailand Research
Fund through the project“Application of Genetics and
Biotechnology for Sustainable Development of Aqua-culture”awarded to U. Na-Nakorn (the Senior Research
Scholar 2003). The authors thank Mr. Pedro Bueno,
DirectorGeneral of theNetwork forAquacultureCentres
in Asia and Pacific (NACA) for improvement of the
English. We thank the referees and the editor for their
invaluable comments which significantly improved the
manuscript.