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Genetically Modified Black Tetra Causes Concern Among Scientists

Available in the aquarium fish hobby, the electric green tetra is a black tetra with genes from a fluorescent coral.

September 4, 2012

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electric green tetra

The electric green tetra is a genetically modified Black tetra. Photo credit:
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zebra danios

Genetically modified zebra danios swim with normal danios. Photo credit:

The electric green tetra, a genetically modified black tetra (Gymnocorymbus ternetzi) fish that is fluorescent green in color, has become cause for concern by scientists who say that if released, the fish could upset the ecological balance in South America or Florida, according to a report in the Washington Post. The scientists say that if released into the wild in their native South America, the electric green tetra could start interbreeding with the black tetra and cause the spread of a fluorescent coral gene in the native black tetra populations.

My worry is that they’ll be such a novelty that they will be imported back to South America and kids will let them go and they’ll start interbreeding with fish whose genomes are very similar, Barry Chernoff, a freshwater fish biologist and chair of the environmental studies program at Wesleyan University in Middletown, CT told the Post. We would see the spreading of the fluorescent coral gene in the native fish.

Yorktown CEO Alan Blake, who markets the fish under the GloFish brand name, said that the black tetra was chosen specifically because it is nonaggressive and apparently does not show any tendency to be an invasive species. He cites the 60 years in which the black tetra has been sold in the aquarium hobby and says that there has never been a concern with the fish ecologically. He also says that there have been reports of black tetras found in Florida but says there is no evidence that the fish has become established in Florida waters, in spite of some 30 types of invasive fish that now thrive in the Sunshine State.

In spite of Blake's assertions, scientists are still at a disagreement with regard to this genetically modified tropical fish. Paulo Petry a Nature Conservancy freshwater fish specialist in Latin America told the Post that fish behavior can't be predicted in labs and the fish should not be sold in regions where there is even a remote chance that it could become established in the wild.

The electric green tetra, which is identical to the black tetra except for its fluorescent green color that comes from genes of a fluorescent coral, glows in the dark under black light. In addition to the electric green tetra, Yorktown has also genetically modified the zebra danio. The fish can be purchased in all states except California. California requires an ecological review that the company did not want to pay for to determine if the fish would be allowed into the state. These fish are also banned in Canada Europe, New Zealand, and other countries.

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Genetically Modified Black Tetra Causes Concern Among Scientists

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Reader Comments

Levi    Jacksonville, FL

3/13/2015 12:52:59 PM

they are just fish!

scott    san tan valley, AZ

12/22/2012 6:12:50 PM

would never own any genetically modified species! mother nature gives us enough beauty, should not mess with her.

Angelo    San Leandro, CA

9/9/2012 12:43:31 AM

The neon tetras are pretty cool though...

Aaron    Calgary, AB

9/5/2012 7:28:58 PM

I was just about to say that!
If you think of it black skirt tetras are black making them hard to see in the water so that = safe from predetors. But add a neon green skirt tetra and they would get eaten up by any predator that sees them. SO IF these fish did get relesed into the wild they wouldnt survive from predators!
I thought I saw these fish up here in Canada but they were labled as fruit fish and came in pink, blue and green....

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