Originally developed to monitor water for pollution, the genetically altered zebra danios are red and glow under black lights, and are being sold as "the nation's first officially sanctioned genetically modified pet," according to author Griff Witte. Even though the Food and Drug Administration has ruled that the fish does not need to be regulated, debate has been sparked over biotechnology. "Most scientists agree GloFish poses little danger to human health or the environment, but a public-interest group has sued the government to stop its sale until the fish can be reviewed more thoroughly," with some experts pointing out "that the science behind gene alteration is in it infancy, and the ramifications of such rapid changes in the genetic code are unknown." Others question "whether such cutting-edge science should be used for such frivolous purposes." Proponents of the GloFish point out its value as a tool for teaching people about biology. There are also such potential advantages as genetically modified pets that will not aggravate the pet owner's allergies or animals that will not be as susceptible to ailments such as hip dysplasia.