| Summary: | Thesis (MSc)--University of Stellenbosch, 2007. ENGLISH ABSTRACT: The indigenous abalone Haliotis midae is one of the most remarkable and highly exploited species of marine molluscs in South Africa. It is the only species of southern African Haliotidae to be commercially reared and has been successfully cultured for almost two decades. Its short history of domestication along with market demands and the need to develop efficiency in the production process has resulted in an increased interest in the possible genetic improvement of this species. The unhurried growth rate associated with H. midae is a cause of particular concern to the industry, predominantly with regards to profitability and competitiveness in the market place. A modest amount of work has so far been directed at establishing a means of enhancement for selective breeding on the commercial level. Genetics plays a key role in the establishment of successful improvement programmes in various aquaculture species. The aim of this study was to develop species-specific microsatellite markers for the abalone and subsequently perform parentage assignment on farm produced animals entered into a growth performance recording scheme. Animals were obtained from the hatcheries of three commercial abalone farms situated in the Walker Bay region in the Western Cape. Microsatellites were isolated using the enrichment-based FIASCO method, and characterised into perfect, imperfect and compound repeats according to the structural nature of their repetitive units. From the partial gDNA libraries obtained and 365 screened colonies, a total of 54 loci were located. PCR primers were designed for 36 markers and the 15 primer pairs that displayed loci with the highest level of polymorphism were subsequently chosen for fluorescent labelling. The markers were tested on a subset of 32 wild H. midae individuals to determine their usefulness and efficiency in genotyping. Five markers, along with five others that were previously designed, were chosen for assigning parentage to ...
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