The aim of this study was to estimate donor-oyster derived heritability and genetic correlations for pearl quality traits in the silver-lipped pearl oyster, P. maxima; namely pearl size, colour, lustre, shape and complexion. As future breeding programs for pearls are likely to involve oysters that will be reared in geographically disparate locations we also evaluated the potential impact environment G × E interactions may have on the realization of genetic gains for pearl quality traits.
Aquaculture production systems in developing countries are largely based on the use of unimproved species and strains. As knowledge and experience are accumulated in relation to the management, feeding and animal health issues of such production systems, the availability of genetically more productive stock becomes imperative in order to more effectively use resources. For instance, there is little point in providing ideal water conditions and optimum feed quality to fish that do not have the potential to grow faster and to be harvested on time, providing a product of the desired quality.
The annual production from global aquaculture has increased rapidly from 2.6 million tons or 3.9% of the total supply of fish, shellfish and mollusks in 1970, to 66.7 million tons or 42.2% in 2012, while capture fisheries have more or less leveled out at about 90 million tons per year since the turn of the century. Consequently, the future seafood supply is likely to depend on a further increase of aquaculture production. Unlike terrestrial animal farming, less than 10% of the aquaculture production comes from domesticated and selectively bred farm stocks.
There are 58 species of Clarias recognized in FishBase (as of January 2009), 33 in Africa and 25 in Asia. Aquaculture of clariids is important with 30 countries reporting a total production of over 300 000 t worth nearly US$400 million in 2006. Most production involves the African Clarias gariepinus (Burchell, 1822) and three Asian species, Clarias batrachus (Linnaeus, 1758), Clarias macrocephalus (Günther, 1864) and Clarias fuscus (Lacep'de, 1803). In much of Asia, hybrids of introduced C.
Aquaculture is predicted to continue playing a major and ever increasing role in meeting human's needs for protein. Production systems in developing countries are largely based on the use of unimproved species and strains. As knowledge and experience are accumulated in the management, feeding and animal health issues of such production systems, the availability of genetically more productive stock becomes imperative in order to more effectively use the resources.
Selection for harvest weight was performed in a fully pedigreed synthetic line of Nile tilapia (Oreochromis niloticus) in Egypt for two generations. Records were available over three spawning seasons (2002, 2003 and 2004) for weight at the beginning of communal rearing (initial weight), harvest weight and survival rate. The data set consisted of 9,267 progeny records from 214 sires and 323 dams. Phenotypic and genetic parameters, as well as response to selection, were estimated fitting an animal model as well as a sire and dam model to the data.
The quantitative genetic basis of fatty acid composition was examined in the Genetically Improved Farmed Tilapia (GIFT) strain of Nile tilapia selected for high breeding value for body weight and in the contemporaneous control selected for average breeding value. Gas chromatography analysis of 514 frozen fillet samples, obtained from the offspring of 104 sires and 154 dams from two generations in 2006 and 2007, showed that the fish possess all important fatty acids (FA), with the amount of omega-3 polyunsaturated fatty acids being 3.6%.
Second Workshop of the Genetic Improvement of Freshwater Prawn Macrobrachium rosenbergii, Central Institute of Freshwater Aquaculture, Bhubaneswar, India, 22-24 June 2009
The WorldFish Center and its research partners have recently made efforts to develop genetically improved carp strains. This paper analyses the comparative performance of the genetically improved carp strains on both average and efficient farms in four carp-dominating Asian countries (Bangladesh, India, Thailand and Vietnam). The results show superior performance of improved strains in terms of body weight and survival rate on both average and efficient farms. On an average farm, the improved carp strain gives 15% higher body weight at harvest in India to 36% higher in Bangladesh.
Some relevant components of selection program theory and implementation are reviewed. This includes pedigree recording, genetic evaluation, balancing genetic gains and genetic diversity and tactical integration of key issues. Lessons learned are briefly described – illustrating how existing method and tools can be useful when launching a program in a novel species, and yet highlighting the importance of proper understanding and custom application according to the biology and environments of that species.