Genetic stock identification is increasingly needed for fisheries management. Genetic technologies are being developed to increase food production from aquaculture and to document and evaluate aquatic species, subspecies and strains for use in breeding programs. This volume of proceedings is a compilation of state-of-the-art reviews on aquatic genetic resource issues and summaries of discussions and recommendations from one of the few “think tanks” focused on aquatic genetic resources policy.
A selection programme using Best Linear Unbiased Prediction (BLUP) method for the estimation of genetic merit was implemented by the Department of Fisheries Malaysia (DOF) in collaboration with the WorldFish Centre. This collaborative programme provided opportunities for further improvement of the GIFT strain in Malaysia. The overall aim of the present study was to evaluate the performance of GIFT strain during the long-term selection programme in Malaysia.
To satisfy increasing demands for fish as food, progress must occur towards greater aquaculture productivity whilst retaining the wild and farmed genetic resources that underpin global fish production. We review the main selection methods that have been developed for genetic improvement in aquaculture, and discuss their virtues and shortcomings. Examples of the application of mass, cohort, within family, and combined between-family and within-family selection are given.
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).
Suggestions for controlling the domestication of tilapia improved strains are given regarding: 1) the population that serves as foundation stock; 2) the breeding system employed; and 3) the process used for selecting brooding stock.
The Hilsa shad, Tenualosa ilisha popularly known as ‘Hilsa’, is one of the most commercially important fish species in South Asian countries. The species is widely distributed from the Persian Gulf to Bay of Bengal and ascends into estuaries, rivers and brackish-water lagoons of the Indo-Pacific region. Recently, the availability of hilsa has drastically dwindled in aquatic systems across this region, due to anthropogenic pressures, mainly intensive fishing and river obstruction by dams and barrages. Climate change may also be contributing to the declining populations.
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.
Genetic parameters and selection responses were obtained for harvest body weight of blue tilapia (Oreochromis aureus) from data collected over three generations in a selected population. A total of 18 194 records representing 186 sires and 201 dams were used in the analysis. Within generation heritability estimates for harvest body weight ranged from 0.18 to 0.58. When data from more than one generation were included in the analysis, heritability estimates became more stable (0.33–0.40) and it was 0.33 when all data were included in the analysis.
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.
A commercial breeding nucleus of coho salmon (Oncorhynchus kisutch) was established in Chile in 1997. This nucleus consists of two independent populations corresponding to different year-classes (even and odd, depending on the spawning year), which have been successfully selected for harvest weight (approximate genetic gain per generation of 10%). In order to constrain the buildup of inbreeding a strategy based on avoiding full-sib mating in each generation was used.