Improved fish breeds show increased potential for aquaculture
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WorldFish work to strengthen the technological foundations of aquaculture has made major advances in recent months, with the release of new generations of improved fish lines and the use of genomic selection tools to introduce disease resistance and feed efficiency traits.
WorldFish and its partners have been breeding genetically improved farmed tilapia (GIFT) since the late 1980s. The latest GIFT generation developed under this project shows that selective breeding for increased growth is still delivering gains of about 10 percent per generation.
The Abbassa strain developed in Egypt is also showing strong performance, and fish farmers are reaping the benefits. “Last year my production using the common strain was around 9.5 metric tons per hectare,” says Mohamed Gamal, an Egyptian fish farmer who received the improved Abbassa strain in 2016. “This year, the production of the Abbassa strain reached 12 metric tons per hectare.”
Furthermore, a WorldFish survey conducted in 2016 and 2017 of 83 farms in four major tilapia-producing districts showed that the Abbassa strain had higher growth and required 13.2 percent less feed than another commercial strain to achieve the same production. As a result, the Abbassa strain generated significantly higher profits (47.8% ) per feddan (0.42 hectares) compared to the other strain.
These improved strains of tilapia are spreading rapidly. More than 70 percent of tilapia production in the Philippines comes from GIFT or GIFT-derived stock, as does around 50 percent in Thailand and 20 percent in Vietnam.
First breeding programs for catla and silver carp
Work on carp species is at an earlier stage but is hoping for similar impacts. In 2017, the project established two breeding programs in Bangladesh for catla and silver carp—the first in the world—and harvested the first improved generation of rohu, which, like tilapia, showed a growth gain of around 10 percent.
Yet faster growth alone will not deliver sustainable fish farms. As a result, the project is turning its attention to other characters and factors that influence farmers’ fish enterprises such as disease resistance and feed efficiency. Based on a roadmap created with global experts at a WorldFish-hosted fish breeding workshop on 23–24 May 2017 in Edinburgh, UK, the research is using genomic selection tools to introduce these characteristics into its improved tilapia strains.
Genomic selection has enabled a step change in the rate of genetic improvement of terrestrial livestock and has the potential to do the same in fish. Moreover, incorporating new traits in the GIFT breeding program will help fish farmers prepare for future challenges such as climate change. This will particularly benefit farmers in Africa and Asia, where tilapia is critical for food security but where there is often limited access to improved fish breeds suited to local conditions.
Selective breeding of tilapia and carp populations and new tools to support this is a key part of the CGIAR Research Program on Fish Agri-Food Systems (FISH) and supports WorldFish efforts to increase the productivity of small-scale aquaculture to meet growing global demand for fish.