20 DECEMBER 2017 • WORLD AQUACULTURE • WWW.WAS.ORG feed in tilapia culture started in 1980-1981 (Shiau and Liao 2006). Ingredients in fish and prawn feeds in Taiwan are relatively simple and are mainly imported. For example, white fishmeal, mainly incorporated into eel feeds, is imported from Japan; soybean meal and wheat flour from the USA; and brown fishmeal from Japan, West Germany and South America; and α-starch and wheat gluten, used as binders for eel and shrimp feeds, come from Southeast Asia and Australia, respectively. Shrimp Aquaculture Research Before 1969, shrimp culture was practiced in Taiwan using natural seed and in polyculture with milkfish. Since then, owing to success in artificial seed production, shrimp culture enterprises expanded very quickly. At first, farm area and stocking density increased, and then the culture system changed from polyculture to monoculture. A maximum production level of 100,000 t was achieved in 1987. Since 1988, however, shrimp production has dropped significantly due to several problems, including disease outbreaks. To revive the shrimp culture sector, a series of research projects on viral disease and culture technology have been undertaken. For culture technology, polyculture and closed recirculating system are the main points of research. A decade of research and field testing has indicated that indoor recirculating intensive shrimp culture can efficiently prevent disease and concurrently save water and land resources. However, the technology is not yet fully mature, dissemination is still inadequate, and costs for facilities and electricity are relatively high. As such, the price received by farmers for the shrimp produced must be >US$ 13/kg for the system be cost-effective. The other alternative is to improve outdoor shrimp culture systems for effective removal and treatment of sludge and generally improving the culture environment. Considering the Taiwan shrimp consumer market demand, it is worthwhile to invest more manpower and financial support to improve shrimp culture systems to reduce production costs and provide cheaper and better-quality shrimp products (Shyu et al. 2016). Tilapia Aquaculture Research Tilapias are cultured in more than 140 countries and are among the most cultured fish worldwide, with production exceedingd 5.5 million t in 2015. Nile tilapia Oreochromis niloticus is the main cultured species and most responsible for the significant increase in global tilapia aquaculture production. Tilapia was introduced to Taiwan more than 70 years ago. It has become an important farmed fish for domestic consumption and export as frozen fillets to the key markets of Japan, South Korea and the United States. At present, selective breeding for the genetic improvement of quality-based Taiwan tilapia is a critical task. Genetics and broodstock management strategies of genomic and molecular marker-assisted selection and breeding are important for promoting improved varieties of seeds of Taiwan tilapia species. Highly polymorphic genetic markers have been used to identify association between markers and expression quantitative trait loci for muscle growth, sex determination, pigmentation, immune response, and stress response pathways related with family relationships in different tilapia species and their hybrids. Initially tilapias were considered to be more resistant to bacterial, parasitic, fungal, and viral diseases compared to other species of cultured fish. However, strains of genetically improved farmed tilapia (GIFT) with good growth performance are susceptible to bacterial and parasitic diseases (Amal and ZamriSaad 2011). Streptococcus iniae and S. agalactiae are the major bacterial pathogens affecting tilapia production in the world (Evan et al. 2006). Recently, emerging viral diseases of tilapia causing by herpes-like DNA virus tilapia larvae encephalitis virus (TLEV) (Shlapobersky et al. 2010) and orthomyxo-like RNA virus tilapia lake virus (TiLV) (Eyngor et al. 2014) threaten tilapia aquaculture in Asia and elsewhere. Selective breeding of new GIFT strains for disease-resistance is an urgent issue for the sustainability of tilapia aquaculture. Researchers working on molecular breeding in Taiwan are identifying functional protein-coding genes, microRNAs (Huang et al. 2012) and associated Type I DNA markers for marker-assisted selection of growth enhancement, monosex male, red body color, disease-resistant, cold-tolerant or salinity-tolerant tilapia strains by analyses of transcriptomes and the whole genome assembly (GCA_001858045.2) of Nile tilapia. Additional Biotechnology Research In recent years, the government has committed to establishing the biotechnology industry and the application of biotechnology in aquaculture practices is within its scope. Research on rapid disease diagnosis systems, high-quality seed production systems, safety and traceability of fisheries products, vaccine development, molecularbased breeding of fish and shrimp, and functional feed additives are among the highest priority areas. Aquaculture research funding in Taiwan is largely provided by the Ministry of Science and Technology and Fisheries Agency and the Council of Agriculture. Other funding sources are also available from the aquaculture industry or local academic societies and associations. The Commercial Aquaculture Sector There are many successful Taiwanese aquaculture companies active in Taiwan and throughout the Asia-Pacific region, including China. The leading aquafeed producers in Taiwan are Grobest Group, Uni-President Enterprise Corporation, Da Chen Greatwall Sea grape.
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