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 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).
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.
Solomon Islands has a population of just over half a million people, most of whom are rural-based subsistence farmers and fishers who rely heavily on fish as their main animal-source food and for income. The nation is one of the Pacific Island Counties and Territories; future shortfalls in fish production are projected to be serious, and government policy identifies inland aquaculture development as one of the options to meet future demand for fish.
Effects of stocking density on the growth, production, and economics of all-male tilapia (Oreochromis niloticus) were investigated in a rain-fed rice-fish ecosystem for a period of 120 days. Fish were stocked at the rate of 4000, 5000, and 6000 ha-1 in treatments T1, T2, and T3, respectively. Water quality was suitable for fish culture. Significantly higher growth was observed in T1 as compared to other treatments. SGR ranged from 1.26 to 1.51. Survival varied between 79% and 88% with treatment T1 producing the highest survival.
This study was planned to determine the grazing rate of O. niloticus from both toxic and non toxic strains of Microcystis aeruginosa with its effect on fish health through study of some clinical signs, hematological and biochemical parameters.
In this article, the authors investigated aquaculture production of Asian tiger shrimp, whiteleg shrimp, giant river prawn, tilapia, and pangasius catfish in Bangladesh, China, Thailand, and Vietnam by using life cycle assessments (LCAs), with the purpose of evaluating the comparative eco-efficiency of producing different aquatic food products.
Tilapia is the main cultured fish species in Egypt, contributing 43.5% of farmed fish production and 24% of total fisheries production. The main problem facing tilapia producers is early reproduction before fish reach marketable size, leading to overpopulation and smaller fish at harvest. Approaches to this problem include the use of all-male hybrids and hand-sexing to remove females.
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%.
Identifying locally available ingredients to formulate tilapia feed that is nutritious but cheaper than existing commercial feeds promises productivity, livelihood, health and environmental benefits, especially by enabling local feed manufacturers.