Two public interest groups that want to block sales of fluorescent zebra fish - the first US biotech household pet - sued the federal government.
The legal case on Wednesday asks a federal judge to order the Food and Drug Administration and the Department of Health and Human Services to halt sales of the trademarked GloFish until the government regulates the genetically modified fish.
The normally black-and-silver zebra fish glow bright red under black or ultraviolet light, thanks to a gene transplanted from a sea anemone. Sales of the Florida-grown fish began this month everywhere in the country except California, which banned the fish in December.
Not regulating the GloFish sets "a dangerous precedent for all future gene-altered animals, whether created as food or pet fads," said Joseph Mendelson, legal director for the Centre for Food Safety, which filed the suit along with the Center for Technology Assessment.
The FDA said last month it would not regulate the fish because it is not intended for human consumption. A spokeswoman said on Wednesday the FDA stands by that statement.
GloFish are a product of Yorktown Technologies LLP of Austin, Texas. The company's chief executive, Alan Blake, said scientific studies had shown the fish were safe and the lawsuit was without merit.
The federal suit, filed in Washington, DC, alleges the benign
fluorescing gene was inserted using other genes derived from animal and human viruses, as well as antibiotic resistant bacteria.
The suit alleges the hidden genes can threaten human and animal health if the biotech fish are released and consumed by other fish that eventually are eaten by humans.