Man said, “Let there be Glofish.” And so it came to pass that fish began to glow. You no doubt remember when Dolly the lamb made worldwide headlines in 1996 as the first successfully cloned mammal in history. What few people realize is that the cloning of animals produced from embryonic tissue dates back to 1958. What fewer people realize is that cloning and stem cell research is but a mere fraction of the experimentation being done in the field of bioengineering. Biogenetically engineered hybrids of previously existing species are being invented and even patented with ever increasing frequency.
The Golfish just turned 10 years old. Happy birthbay! Just a decade ago there was no such thing as a Glofish. What exactly would be the purpose for making a fish glow? Good question, especially if you stop to consider how much easier they would for a potential predator to find and decide they might make a tasty snack. But the goal was not to create a fish that screamed out, “Here I am. Come eat me.” Nor was it to create an entirely new species for the thriving global ornamental fish industry. In fact, monetary gain did not come into play at all when in 1999 when Dr. Zhiyuan Gong and his team of bioengineers at NSU (the National University of Singapore) decide to genetically modify a preexisting freshwater species of fish to make it glow. So if eradicating a nuisance species by making it more easily detectable, or accumulating a vast fortune by creating a “must have” novelty item for the hungry fish hobbyist market was not the objective, then what was? As incredulous as it may sound, the objective was to create a fish that would selectively luminescence when it came into contact with environmental contaminants. Hmmm… a fish that fights pollution by tracking industrial ecological offenders to their source, we might be on to something here! Do you think it was a sheer coincidence that the first Glofish ever created was GREEN?
Selective bioluminescence, this is indeed a lofty goal. How do you incorporate a biologically triggered light switch that automatically turns on in the presence of environmental contaminants? The logical answer is that you must first find a way make an animal glow. Only after the objective of bioluminescence is achieved, can you address the problem of biologically triggered selectivity.
Among the many decisions faced by the geneticists was which fish should be chosen as the most likely candidate. The team decided on a small minnow variety, the Brachydanio reri. These fish are more commonly known as zebra danio or zebrafish throughout most of the world. Although indigenous to India, zebrafish are raised on fish farms for export in Singapore. A commercially raised fish means readily accessible eggs. This may or may not have been a determining factor in their selection.
The scientists then turned to the jellyfish for the initial phase in the creation of their aquatic toxic detective. Aequorea victoria, more commonly known as crystal jellyfish, contains the bioluminescent gene GPF (Green Fluorescent Protein). When injected into a zebrafish embryo, the addition of GPF produced a fish that absorbed and then readmitted light from the green spectrum. A variant of this jellyfish gene caused the resulting offspring to fluoresce yellow. RFP (Red Fluorescent Protein) derived from sea coral of the genus discosoma created zebrafish that luminescence in red. While this scientific feat was amazing in and of itself, it was only the first step in creating a fish that would actually glow when exposed to toxic waste material. What they did create, however, was a previously nonexistent transgenic species that would go on to spark controversy around the world.
The creation of the world’s first florescent fish was bound to draw some attention. It did not take long for news of NUS’s success to reach the desks of entrepreneurs Alan Blake and Richard Crockett. They wasted no time in sewing up exclusive worldwide rights for the sell of Glofish. Yorktown Technologies of Austin, Texas then went to work commercially raising Glofish for the thriving aquarium trade industry. Fortunately for Blake and Crockett, fish farms for the production of zebra danios had been in existence in the southern parts of United States since as early as the 30s. It was not much of a leap to raise a species that is only a single gene removed.
Glofish were slated to hit the market in late 2003. The question now becomes how should both national and regional governmental agencies react to the idea of a genetically engineered organism being unleashed on the general public? The European Union outright banned the sell of all genetically modified organisms within its member countries. The distribution or possession of Glofish is also prohibited in Canada, Australia, and Japan. Glofish are legal in 49 states in the U.S. The State of California issued the Environmental Quality Act to halt the sell of GloFish before they were even available to the public. Who would have thought something as benign as an ornamental aquarium fish would create such a stir? Ironically, fluorescing quickly became top sellers within the aquarium trade in most of Asia and in the U.S.
Bioengineered transgenic manipulation aside, environmentalist have long expressed concern about the potential ecological ramifications of nonnative species being intentionally or even accidentally introduced to an established ecosystem. It is for this same reason that the sell or possession of piranha is illegal in most of the U.S. There are document case studies where the global availability of various species of aquarium fish has resulted in the introduction and proliferation of non-indigenous species. One such example is the plati fish (Xiphophorus maculates). The plati is native to southern Tamaulipas and northern Vera Cruz, states in northeastern Mexico. This species is particularly well suited for slower moving freshwater systems such as canals, ditches and warm springs. They have established significant populations in the United States in the canal systems of Tampa Bay and Gainesville, Florida. They have become naturalized in the state of Montana. They have also acclimated to the freshwaters of Columbia, Singapore, and Hong Kong. Hong Kong ecologists report that these “illegal aliens” are creating an adverse impact on their aquatic ecosystems due to the plati’s prolific breading habits. The tilapia, a cichlid native to the Amazon River Basin, has been deemed a nuisance species in the southern US after populations sprang up from what was undoubtedly an aquarium trade related release into the wild.
Do Glofish pose a threat? The end of World War II marked beginning of an explosion in the aquarium trade industry. There is only a single gene separating Glofish from their natural counterpart, zebra danio. Over 200 million of these fish have been imported and sold in the U.S. alone over the past half century. Zebrafish are incapable of surviving the temperate water conditions in all but the most southern states. To date, there has not been a single report of an established reproducing population in the wild anywhere in the United States.
Since Glofish went on sale in 2003, scientists in various parts of the globe have successfully incorporated the fluorescing gene into rabbits, pigs, dogs and cats. The transition to mammals was undoubtedly inevitable. Given the rate of scientific progress perhaps it is understandable why many nations around the world decided it prudent to outright ban transgenic organisms for any purpose other than scientific research. That said; Glofish by their very nature are confined to a captive environment. If zebrafish, accidentally or intentionally introduced into the wild, posed a quantifiable ecological threat to the planet’s freshwater ecosystems that threat would have been apparent long before geneticists infused a fluorescing gene into their genome. Adding a fluorescent fish to your aquarium is a far cry from buying a glowing kitten or puppy dog for your kids. Half the dogs and cats in the neighborhood won’t be mysteriously glowing under a black light a year later.
Glofish don’t need a lot of room. Any desktop nano tank. is large enough to keep an entire family of them in. They don’t take up much space and they make great accent pieces to your dcor. If you enjoyed this article, discover more up to date info about everyone’s favorite freshwater aquarium fish by going to our fish buying guide.
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