Exctinction threat from transgenic fish


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A new report suggests that there is a risk of some species of fish becoming extinct if certain transgenic fish are released or escape into the wild.

The study by scientists from Purdue University, USA, is due for publication this week in the online journal of the Proceedings of the National Academy of Sciences (PNAS). Lead author Richard Howard told UPI: "This study shows for the first time that genetically modified fish have better mating success than wild-types."

The scientists worked on the Medaka, Oryzias latipes, and inserted a salmon growth hormone gene into the fish, resulting in fish that were 83% larger than normal wild-type counterparts. The study showed that these larger transgenic species out-competed wild males during spawning by fertilising up to 75% of broods. Based on this, the study showed that some species could be driven to extinction within 50 generations.

The GM fish that have gone on sale in aquarium shops around the world do not contain growth hormone genes, and are claimed to be sterile, however, the techniques are being applied to the production of farmed fish, such as salmon, to produce fish that reach a saleable size in record time.

Howard told the UPI that he plans to assess the environmental impact of the GloFish: "Right now the indications are that they would not, because the gene put into the fish doesn't increase body size or affect things that would necessarily elevate the mating success of males."