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.
The aim of this study was to examine genetic variation in reproductive traits and to estimate correlated responses in such traits to selection for high growth rate in the GIFT strain of Nile tilapia (Oreochromis niloticus).
Details are given of a simple method for the year-round production of Clarias gariepinus fry in homestead concrete tanks. Procedures involved regarding the induced spawning of the fish, egg hatching and rearing of fingerlings are described.
Three discrete generations of GIFT fish (Nile tilapia strain, Oreochromis niloticus; a total of 10,065 fish with pedigree and phenotypic information) were tested in pond and cage culture environments to determine genotype by production environment interaction between both environments in Malaysia. Live weight (selected trait), standard length, body depth and width were recorded. A bivariate animal model was used to estimate variance and covariance components, whereby the homologous body traits in pond and cage environments were treated as genetically distinct traits.
The main objective of this paper was to report more reliable estimates of the genetic variation and the genotype by test environment interaction for harvest body weight in the GIFT population in the Philippines than could be obtained from the base population by using the data from the five generations following the base population and that covers a wider span of test environments than the later experiments referred to above. Included are also estimates of the genotype by sex interactions for body weight.
Hilsa (Tenualosa ilisha) is a major fishery resource in the Bay of Bengal. In order to ensure the sustainability of this resource, through effective management measures, information is required on its distribution patterns, migration routes and breeding sites. This study fills these knowledge gaps in Myanmar’s Ayeyarwady Delta. The findings are based on systematic gathering of local ecological knowledge among experienced fishers in thirty-two sites.
A brochure to describe the research works in Bangladesh by the WorldFish center
Aquaculture operations should include a comprehensive biosafety program because of the risks they may impose on biological resources in the environments into which cultured organisms may escape. Risk assessment incorporates hazard identification and risk analysis. Risk analysis encompasses describing the likelihood that a hazard and its consequences will occur and the severity of realization of a consequence.
During the development of the GIFT (Genetically Improved Farmed Tilapia) strain in Philippines sperm was frozen from a sample of males from founder stocks and subsequent generations. In this paper a comparison of progeny performance produced from cryopreserved sperm from the base population of the GIFT strain, with progeny from freshly colleted sperm from the ninth generation produced in Malaysia was conducted. Differences in performance were used to estimate the genetic change over these nine generations.
Aquaculture species are being domesticated and improved through genetic enhancement. Despite the benefits of improved fish in terms of increased production, there are risks associated with conservation of biodiversity when the introduced strains/species escape in natural waters. This is especially important in Africa which is one of the world’s repository of diverse freshwater fish fauna and home to native tilapias.