The "up-to-9" year claim in these spheres seems real, the shrimp used in these spheres are called opae ula known for their unusual longevity and hardiness:
Recent popularity of ʻōpaeʻula as a low-maintenance pet in Hawaiʻi and elsewhere has brought this otherwise obscure decapod crustacean into popular consciousness. A long-lived species, ʻōpaeʻula have been known to live for as long as 20 years in captivity. Sexes are difficult to distinguish, but gravid females carry clusters of red/maroon eggs under their pleopods, and early larvae are planktonic filter-feeders.
But the average life-span is 1-2 years because the shrimp slowly suffocate or starve to death in the tiny air-tight spheres when the environment becomes unbalanced. They do make cool paper weights but I don't want my pets living like that.
I'm going to try to make my own
(don't know about these instructions), but in a larger (~1 gal) container with a close-able lid and a tiny filter. Water change will hopefully be @ a minimal, once a month or two if any. Balancing the nitrogen/oxygen cycle might be tough. If I get it right I'll have a neat close-to-zero maintenance tank.
Some further reading: 1
| Pictures of natural environment
So I was Googling self-sustaining aquariums and ran across this:
It's expensive, but the site claims that they last 2-7 years (but on order page says replacement 6/12 months). Anyone have any experience with these? Says it contains -- "seawater, red shrimp, microbes, algae, Gorgonia sprig, gravel, shells, and glass."
Seems really gimmicky, from the client testimonials:
Two of my shrimp have been living since 2002! They are almost 9 years old and still doing great. The people at ecosphere know what they are doing.
What kind of shrimp lives for 9 years!?!