Why were Glofish developed?

Originally there was an experiment using specific genes from a Jellyfish and injecting/ joining them into the DNA of different species of fish. The result was a fish that glowed. How and why this technology and method was passed on to the people who produce the genetically altered Zebra Danio (Brachydanio rerio) is beyond my knowlege but I guess it goes to prove that if something can be done and someone can see a financial benefit in doing it, then it will be done.