A general review on aquaculture in Asia： a focus on Anguilla eel.

Abstract

Asia continues to be the dominant aquaculture producer in the world. In 1999, aquaculture production (38.9 million metric tons valued at US$ 44 .1 billion) in the region comprised 90.9% of the world total. The top ten aquaculture producers were all from Asia. The region also had the highest number of culture species. Among the culture species in Asia, the eels appear to have a high potential for further development in the region. In the last decade, Asia has annually contributed over 95% of the total world production of cultured eels, which increased from 165,31 3 mt in 1990 to 21 7,145 mt in 1999. Culture species is primarily of the Japanese eel (Anguilla japonica). China, Japan, and Taiwan are the top three producers. The eels are highly suitable culture species because of their high unit production, high survival rate, strong disease resistance, and high nutritional quality. At the present, the unstable glass eel and elver supply from the wild,the unsuccessful completion of the eel's life cycle in captivity, the insufficient suitable land and freshwater resources, and the limited consumption markets restrain the further development of the eel aquaculture industry. Nevertheless, modest results have been achieved so far from the research aimed at resolving these limiting factors. Final gonadal maturation can be induced with hormonal treatments . In the larval rearing aspect, the metamorphosis of the larvae from the pre-leptocephalus to the leptocephalus stage has been successfully achieved. Stock enhancement and sea ranching using hormone-treated adult eel is being conducted to augment the wild stock. Effective culture systems are also being developed to address the problem on insufficient suitable land and freshwater resources. Thus, the future of eel aquaculture appears bright. If the breakthrough on captive breeding were realized and eel markets were expanded, eel aquaculture would be at the forefront of the Asian aquaculture industry in the early decades of the 21 st century .