Over at Make Magazine they're celebrating the long life of their biosphere companion George — a very hardy little ghost shrimp. Three years ago they put together a guide for the pages of Make on how to build your own micro biosphere. Ghost shrimp are only supposed to survive for three months or so in a biosphere environment. They had this to say regarding George's longevity:
The water's a little cloudier three years in, and we've had a couple of scares when the shrimp molted and then hid in his seashell home for a few weeks while he grew a new exoskeleton. But during his encampment he's appeared on television as part of a how-to episode of KQED's Quest, been shaken and turned upside down by curious (and slightly unruly) kids at an elementary school, and traveled to at least two Maker Faires.
For three years George has farmed his little self-contained world and shows no signs of slowing down. Given that you can recycle a jar, get the basic materials like sand, water and pond samples for free, and a ghost shrimp costs next to nothing at a well-stocked pet store, building your own biosphere is a cheap project. Check out PDF guide at the link below or visit this collection of biospheres submitted by Make readers.
Table Top Biosphere [Make]