Those looking to spice up their aquariums with some controversial little fish will get the chance this week — though they may have trouble immediately finding the genetically engineered, ...

Move over, Nemo. There's a new star in the fish tank, and this one really shines. The fish, marketed under the trademark name GloFish, are actually zebra danio, an already common pet-trade species.

GloFish are unique creatures with vivid colors that will brighten up any tank. Scientists created them to help with environmental studies, but they have quickly gained popularity in home aquariums.

A fluorescent fish that will be on sale in pet stores has exposed a gaping hole in the United States' ability to regulate the sale of genetically engineered animals. Despite growing concern over the ...