As I write, a dozen brine shrimp dart about in the bowls on my desk. They nibble on green algae coating the rocks inside. I have never fed them, nor cleaned the bowl, nor aerated their water. In fact their home is sealed airtight in a glass globe; nothing goes in or out. They are completely carefree pets, living in a completely self-sustaining world. The algae produce food and oxygen from room light, the shrimp and snails make carbon dioxide for the plants. Together all three organisms support each other with no input from me, other than admiration. Their globes are little sustainable planets of sorts, a balanced ecosystem that could in theory continue indefinitely. One of my spheres thrived for many years before accidently being smashed.

I keep these micro-worlds for three reasons: 1) as a lazy-man’s aquarium (vacation? You could leave for a year and they wouldn’t care), 2) for the constant reminder of how we humans are kept alive by other species, and 3) for the inspiration of a self-sustaining whole system.

My 8-inch EcoCosm next to my printer

You can purchase a ready-made small 4-inch Ecosphere filled with about three shrimp, one snail and a bit of algae, sealed airtight in a perfect glass sphere for $65. The same producer has other larger models, but this one is about the size of a softball. The best place to get one such is at Brookstones store; they are cheaper here than from the manufacturer and Brookstones has a more generous return/exchange policy. The latter is important because a system this small is very sensitive to room conditions, and it is easy to kill off the inhabitants before you find the optimal place in a room — which is warm but (surprisingly) not brightly lit. With this off-the shelf option you get an instant world (works as a gift), but one with few individuals and a somewhat delicate balance.

For the same price you can assemble a much larger — and better– eco-habitat at home by purchasing a small kit from EcoCosm in Hawaii and upgrading the bowl. Order the smallest size micro-habitat ($40), which will give you about a dozen or more Hawaiin brine shrimp, a few snails, and a beautiful bit of porous rock and gravel seeded with algae, all afloat in sea water and packed with a small plastic hexagonal container. Discard the container and substitute a glass fish bowl. I found the best and cheapest spherical bowls are not sold in pet stores but in art stores for use in decorating, holding glass marbles and the like. I got a 8-inch globe for $4. I put in the creatures, the rocks, and then added brine water (1 part sea water to 2 parts fresh water) to top it off. I cut a small circle of plastic to seal the top. The shrimp (about 1/2 inch long when mature) are amazingly visible and active during the day. They constantly distract in a good way.

The question many owners of these brine shrimp/algae worlds want to know is, how long will they live and can the shrimp reproduce? While an individual shrimp can live for up to 5 years, unlike most marine invertebrates, the endemic Hawaiian red brine shrimp (Halocaridian rubra) reproduce very sparingly. This is why they are expensive to culture (and why it is illegal to use wild brine shrimp from the rare anchialine ponds). There are reports of Ecospheres hatching shrimp fry, but they are rare enough to offer little hope yours will. However, even if the shrimp die, the algae will continue to live for decades or longer — an additional ecological lesson.

From my observations of the micro-habitats that friends and I have owned it is clear that the usual cause of decline is too much light. Room light, even dull overhead fluorescent in a Dilbert cubicle, is all the light these worlds need. The tiny orbs of self-sustaining life are great instructional aids. If you like living things nearby but don’t like the slavery of upkeep, these are perfect pet/gardens, and ideal office mates.

May you be a fine god!

– KK

EcoCosm Shrimp Microhabitat
$50 (plus $25 fedex)
Stockly’s Aquariums

4″ EcoSphere
Available from Amazon

Or $65 from Brookstone (currently unavailable)

Manufactured by EcoSphere