Genetic Improvement: Breeding for Increased Growth and Performance in Silver Perch ('Bidyanus bidyanus' Mitchell)

Abstract

The world's food production will have to double by 2025 to provide for an estimated population of eight billion people. Fish is a vital component of food security in developing countries while demand is increasing in the developed world due to greater awareness of the health benefits of eating fish. As capture fisheries have stagnated, aquaculture is expected to play a crucial role in meeting this increased demand for high quality protein. However, there is a large disparity between the need for increased aquaculture production and the genetic quality of stocks available to meet that need. At present, the majority of global aquaculture production is based on unimproved species and strains. If aquaculture is to fulfil its role then improved breeds that use resources more effectively are needed. ... In this study the principles of quantitative genetics have been applied to an Australian freshwater aquaculture species to improve growth rate. Intra-specific heterosis was evident, but not consistent, highlighting the unpredictable expression of dominance genetic variance. This supports recent work in freshwater fish suggesting that the relative weight of dominance and additive genetic variance vary over development time. It also shows that in a highly variable pond environment, non-genetic or environmentally induced size variation can mask the genetic components of growth. Females are the preferred sex for culture and future breeding programs could exploit mono-sex populations. Finally, the overall aim of fish breeding programs worldwide is improved profitability and this study has demonstrated that improvements in growth rate result in improvements in revenue.