Life will go on as long as it can if the existing circumstances can support that life.
You can keep a very large active dog in a 6' x 4' kennel and as long as you provide food, water and clean the kennel, it will live a long life, but not necessarily the best life.
We also "warehouse" people quite well in prisons, concentration/POW camps and nursing homes. Most people don't want to live that way.
It should not be a question, IMO, of what you can stock, but what you should stock in order to provide the best environment for a captive species.