Walk into any commercial pet store and you are bound to find tanks full of the little genetically-modified fish known as “GloFish”. These vibrant, neon fish have grabbed the attention of eager children all across the nation, often with their parents on the hunt for the perfect first pet. But if you take a closer look, it’s obvious that there’s something very different about these fish. GloFish first appeared in 2003 as a genetically-mutated Zebra Danio (Danio rerio) which many people assumed to be a new, exotic breed of fish. However, these fish are simply a breed of common minnow found in the Himalayas. The original intent of this new “brand” of fish was to appeal to customers who wanted fish with the bright colors of a saltwater species while keeping the lower maintenance aspect of a freshwater species. Thus, the GloFish was born, or should I say “engineered”.
GloFish have been genetically engineered to express a protein that allows them to glow, or have bioluminescence. After the public became concerned at the potential environmental and health risks associated with GloFish, the Center for Food Safety sued, but was dismissed in 2005. However, the fish are said to have been engineered with the safety of the environment in mind, being bred to detect toxins in the water. For this reason, many people continue to be skeptical about what impact GloFish can have on the environment, good or bad.
People often question how these fish are any different from their “non-GMO” counterparts. For one, GloFish have a significantly reduced fertility rate compared to common Zebra Danios. This is most likely due to the manipulation of genetic proteins, leading to unstable genetic makeup in fry that survives past fertilization, or the fact that as eggs in the lab, GloFish are subjected to pressure treatment which can cause infertility. Although this can be looked at as a benefit in the case of an accidental introduction to the natural environment, the widespread infertility proves that this breed of danio is an unstable addition to the aquarium hobby. Because this variety cannot replenish its population without the help of genetic engineers and scientists, more and more eggs from the natural Zebra Danio species will be taken out of their gene pool to be subjected to genetic modification.
Although no conclusion has yet been reached about whether the pros outweigh the cons of this new aquarium fish, it looks like the phenomenon of the GloFish isn’t leaving pet stores anytime soon.