Benefits derived from selective breeding have been demonstrated in livestock and in some fish species, but by contrast, there have been few systematic selection programs reported for shrimps. Improving growth rate has been identified as the most important trait in the breeding objective for cultured shrimp species. In the present study we analyzed a four generation data set from a fully pedigreed selective breeding program for giant freshwater prawn (GFP in Vietnam. We estimated phenotypic and genetic parameters for body and carcass weight traits.
This year's report contains the Director General's and Chairman's statements. Also highlighted in the reports, are stories of projects with different partners: 1) CGIAR Research Program on Aquatic Agricultural Systems (AAS) in Zambia. 2) Wetland Alliance project in the Mekong delta. 3) Projects with CARE, the humanitarian organisation in Egypt. 4) Tilapia breeding program with Water Research Institute (WRI) in Ghana. 5) Partnerships with the private sector on sustainable aquaculture enterprise in developing countries.
The Abbassa selection line (developed by selective breeding) and the Kafr El Sheikh commercial strain (widely used in Egypt), both Oreochromis niloticus, were compared at two stocking densities (two and four fish m-2). Harvest weight, length, depth, width and head length were recorded. The Abbassa line showed a superior harvest weight (28 per cent) over the Kafr El Sheikh strain. Males were heavier than females, but the between-sex difference was greater in the commercial than in the Abbassa line (39 and 31 per cent respectively).
Tilapia farming has great potential in Bangladesh. Tilapia promises to become a primary cultured species for freshwater and brackish water ecosystems, and therefore may also be a major source of employment. Bangladesh could become one of the leading Asian countries for tilapia seed production and grow-out farming. This article looks at the current status of Tilapia farming and seed production in Bangladesh.
Preliminary investigations of experimental and commercial stocks of Nile tilapia (Oreochromis niloticus) in the Philippines indicate contamination through interbreeding with wild O. mossambicus. Contamination was determined by polyacrylamide gel isoelectric focusing of skeletal muscle parvalbumins and starch gel electrophoresis of a wide variety of tissue enzymes, from which eye and heart phosphoglucose isomerases were selected as diagnostic markers.
Social interactions often occur among living organisms, including aquatic animals. There is empirical evidence showing that social interactions may genetically affect phenotypes of individuals and their group mates. In this context, the heritable effect of an individual on the phenotype of another individual is known as an Indirect Genetic Effect (IGE). Selection for socially affected traits may increase response to artificial selection, but also affect rate of inbreeding.
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).
Macrobrachiurn rosenbergii is one of the widely cultured freshwater prawn species globally. India was the third largest producer of this species in 2007 and its aquaculture production rose to 43,000 metric tons (t) in 2005 froin less than 500 t in 1995. However, since then production has been declining and in 2008-09 it was 12,856 t, a reduction of more than 70% compared to 2005. There are several contributing factors to this decline, such as slow growth rate, poor survival, disease outbreaks, increase in cost of production, and availability of low risk alternative fish species.
The genetic response in growth traits in a selection program for increased harvest weight in a common carp population in Vietnam is reported. A base population (G0) was established from six carp stocks using single pair mating. Selection was based on high breeding values for body weight at harvest, with a corresponding control group selected on average breeding values of the population.