Dowbrigade

The
genetically engineered pet appears to have arrived. In a development
that is likely to inspire both fascination and alarm, a Texas company
said yesterday that it would soon start selling a genetically
engineered aquarium fish that glows in the dark.

The GloFish, as it is called, is a zebra fish containing a gene from a
sea coral that makes the fish bright red under normal light and fluorescent
under ultraviolet light. Zebra fish, about an inch and a half long, are
normally silver and black.

from the New York Times