{Shoot, I'm at home now and don't have the history sidebar to pull the exact website I was looking at earlier, BUT) IIRC it was referring to a 3 year old Canadian female CC that was mature at 8". So it may have been hurting for food, but it also lived in colder water and in a climate with a shorter growing season. That website also stated the oldest CC (that it knew about) in the wild was a Canadian (I'm sure about this one) one that was 24.
CC seem to be like other species with a large North-South range; the Southerners grow faster and the Northerners live longer.