48 DECEMBER 2014 • WORLD AQUACULTURE • WWW.WAS.ORG Farming of Giant Freshwater Prawn in China Yang Ming A Brief History of Prawn Farming in China There are more than 35 species of the genus Macrobrachium present in China (Li et al. 2007) but the two main species cultured commercially in China are the giant freshwater prawn Macrobrachium rosenbergii and the oriental river prawn Macrobrachium nipponense. As one of the most commercially important farmed crustaceans, the giant freshwater prawn is cultured in many regions of China. As an exotic species, M. rosenbergii was first introduced into mainland China from Japan in August 1976 (Cai and Chen 1995). During this process, the Guangdong Province Fisheries Research Institute (now Pearl River Fisheries Institute, Chinese Academic of Fisheries Science) led propagation research and achieved success in 1977. Postlarvae produced in that year (79,600) were distributed to 14 provinces. Giant freshwater prawn farming first started in southern China and thereafter gradually spread to other coastal provinces and even to northern and inland areas. The start-up phase for giant freshwater prawn development in China extended from 1976 to 1992. Many regions in other provinces carried out farming and breeding experiments after obtaining initial seed from Guangdong. Because breakthroughs in artificial breeding were first made in Guangdong Province and, combined with suitable temperatures there, the farming of the giant freshwater prawn was initially concentrated in the Zhujiang Delta. The culture area in Guangdong Province was 276 ha in 1991, increasing to 520 ha in 1992, with production reaching 598 t (Liao 1994). Beginning in 1993, the giant freshwater prawn farming industry entered a new phase of development, obtaining splendid achievements. The prospect of greater profits attracted many more farmers to giant freshwater prawn farming. Another reason is related to the contagious disease of penaeid shrimp caused by white spot syndrome virus (WSSV), which spread throughout China in 1993. White spot syndrome virus outbreaks caused the farmed production of marine penaeid shrimp to drop dramatically in 1993 as a result of mass mortalities of native cultured species Fenneropenaeus chinensis. As a result, many shrimp farmers began culturing giant freshwater prawn as an alternative species. The farming area reached 1,533 ha in Guangdong Province with a production of 2,601 t in 1993, which was 2.9 times the area and 4.3 times the production of 1992. The phenomenal growth in farming area and production enabled Guangdong Province to rank first in the nation. Earthen pond culture was commonly used during this period and the yield was between 1,5003,000 kg/ha, with a mean net profit of US$ 6,410-9,615/ ha. Profitability was twice as much as traditional fish farming and this greatly stimulated the giant freshwater prawn farming industry. Prawn culture has expanded at a tremendous rate. Giant freshwater prawn production in China increased by 13,000 t every year from 1993 to 2001, reaching an average annual growth rate of 65 percent (Fig. 1). China became the largest global producer of giant freshwater prawn in the middle of 1994. Prawn production in China rose to a peak of 111,282 t in 2001, representing 65 percent of global production. Production declined in 2002 and 2003 as a result of outbreaks of white tail disease (WTD). The pathogen was first found in prawn seed imported from Thailand to Guangdong Province in 1996 (Qian et al. 2006 b). Thereafter, the disease spread rapidly to most hatcheries and culture farms throughout the country, causing widespread losses. The causative agent of WTD has been identified as Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus (XSV) (Qian et al. 2003 b). Diagnostic techniques for WTD use reverse transcriptase-PCR (Widada et al. 2003) and TASELISA (Qian et al. 2006 a) methods. The development of specific pathogen (SPF) free seed production technologies has effectively prevented WTD epidemics. Since then, aquaculture production of giant freshwater prawn recovered gradually. Guangdong Province was the country’s main producing region from 1976 to 2002. In 2003, for the first time, the production of farmed giant freshwater prawn in Jiangsu Province exceeded that in Guangdong Province. Since then, Jiangsu has replaced Guangdong as the province with the greatest prawn production in China. Another popular farmed species, Litopenaeus The start-up phase for giant freshwater prawn development in China extended from 1976 to 1992. Many regions in other provinces carried out farming and breeding experiments after obtaining initial seed from Guangdong. Because breakthroughs in artificial breeding were first made in Guangdong Province and, combined with suitable temperatures there, the farming of the giant freshwater prawn was initially concentrated in the Zhujiang Delta. FIGURE 1. Production (t) of farmed giant freshwater prawn Macrobrachium rosenbergii in China.
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