Tilapia fish gather at a viewing window in their holding tank at the U.S. Food and Drug Administration's (FDA) Center for Veterinary Medicine labs in Laurel, Maryland, November 5, 2009. Reuters Pictures 3 weeks ago

Tilapia fish gather at a viewing window in their holding tank at the U.S. Food and Drug Administration's (FDA) Center for Veterinary Medicine labs in Laurel, Maryland, November 5, 2009.