SACRAMENTO, Calif. - Two public interest groups that want to block sales of fluorescent zebra fish — the nation's first biotech household pet — sued the federal government Wednesday. The lawsuit asks a federal judge to order the Food and Drug Administration (news - web sites) and the Department of Health and Human Services (news - web sites) to halt sales of the trademarked GloFish until the government regulates the genetically modified animal. 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...