The average lifespan of a smallmouth bass is around 6-14 years. If you are going to keep a fish like that as a pet though, i would recommend a largemouth bass instead, because they tend to have a few...
at least 15 inches
Largemouth can get very large . . . larger than a smallmouth can.
Micropterus dolomieu is the latin name for smallmouth bass.
11lbs 15oz. Caught by David Hayes in 1955. The bass was taken in July from Dale Hollow Lake. KY/TN