Who needs a fish tank? The Ecosphere Pod is the coolest pet around. Why? First, there’s nothing to do but sit back and watch. Tiny (but not so tiny that you can’t gaze and watch them) shrimp live and die in a continuous cycle of life, feeding off algae and bacteria withing the fully enclosed glass pod. We have friends who have had these for years and shrimp are still going strong. Schweet.

From the description:

A self-contained, self-supporting ecological system is permanently sealed within this hand-blown borsilica glass sphere. Its careful balance of air, water, plant and animal life was developed as the result of years of NASA research into self-sustaining, bio-regenerative systems where the equilibrium must be maintained for long periods of time, such as long-term space stations. Inside the pod, tiny shrimp feed on bacteria that metabolize organic waste into nutrients for the algae which, in turn, photosynthesize the oxygen needed for the shrimp and bacteria to survive. The life span of the shrimp is up to three years and that of the algae and bacteria is indefinite. Available in 4″, 5 1/4″ or 9″ diameter.