CABI Blog

Last week tropical fishkeepers in New Zealand were alerted to the presence of GM zebra danios available for sale online. The fish, which have been engineered to produce fluorescent proteins, are not authorised for sale in NZ and biosecurity officials have said that any fish traced would be collected and put down.

The fish known as GloFish™ have been branded the world’s first GM pet. They come in a range of colours and really are remarkably attractive. However, what about the ethical situation here? And what about biosecurity?

So do we really need fluorescent fish? Well, it’s not all flippery frippery. The GM zebra danio (Danio rerio) was developed as a model organism to detect environmental pollutants (we have over 1000 records on such experiments in CAB Abstracts). Thoughts then turned to marketing these fish to hobbyists with a suggested retail price of approx. £2.50 (US$ 5) (although reports suggest they fetch US $8-12 dollars); an ordinary danio costs approx. £1.

Then comes the question of biosecurity – most departed fish from my fishtank go down the loo. GloFish have said that as their fish are tropical then they would be unable to survive in a temperate climate. But what about reports (e.g. Cadwallader et al., 1980) of exotic tropical fish surviving in the cooling ponds of powers stations? A spokesperson from MAF Biosecurity New Zealand has said “At the very least, fish should be disposed of into land-based bins and not in a manner where they could get into waterways”.

A further search in CAB Abstracts revealed this paper by Rehbein and Bogerd (2007) on a detection procedure for GloFish should they attempt to land on our shores. Personally speaking, when it comes to choosing new fish for my tank I might just stick to neon tetras!

Identification of genetically modified zebrafish (Danio rerio) by protein- and DNA-analysis.
Rehbein, H., Bogerd, J.
Journal für Verbraucherschutz und Lebensmittelsicherheit, 2007, Vol. 2, No. 2, pp. 122-125, 6 ref.
The import, sale and possession of fluorescent transgenic zebrafish, offered under the name "GloFish" in U.S. aquarium shops, are not permitted in the European Union. A polymerase chain reaction (PCR)-based method has been developed to detect transgenic zebrafish harbouring the gene (dsRed) coding for the red fluorescent protein, originally isolated from the marine sponge Discosoma striata. Two types of PCR have been performed: (i) PCR to detect amplifiable genomic zebrafish DNA was checked using primers specific for the zebrafish parvalbumin gene; (ii) PCR with primers to specifically amplify the dsRed gene. In both PCR systems, genomic DNA isolated from wild type zebrafish was used as control template, in the second PCR system, the plasmid dsRed2-N1 was used as a positive control. Applying this method to several specimens of presumed GloFish from traders in the Netherlands and Germany revealed the presence of transgenic fish. In addition, a rapid method for screening zebrafish suspected to be genetically modified has been developed by measuring the fluorescence of water-soluble protein.

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