Eco is a planet in the space of the galaxy's Gamma Quadrant, the class M homeworld of the Ecocid hive mind civilization. The planet was a lime green color with vast irregular salmon-colored sand dunes and dark spidery blotches. The cities of the planet were organized into Hives, that may have been underground. In the year 2370, there were at least three Hives. In 2370, Benjamin Sisko, Jadzia Dax, and Odo followed the hijacked antimatter tanker Phoenix to Eco. They discovered the Bajoran hijackers and their Ferengi partners in Hive III. (DS9 novel: Antimatter)