Life span varies greatly depending on a number of factors. Shorter growing season areas, up north generally produce fish with longer life spans. I've seen research showing 15-25 years for a lifespan. My dad's friend first stocked CC back in 1993. His original fish were all fin clipped on the adipose. All further fish stocked were not. Two summers ago I caught one of the originals. That would have made it 18 years old and it weighed 25 pounds 4 ounces. A 55 pound fish was caught in a gill net during a lake survey near my house. The lake was formed in 1972. This CC was caught in 2002. Say this fish was a rarity and lived beyond normally expected life span. That could make it 30 years old. They released it unharmed... Would have been pushing a world record had it been caught by rod and reel.