They don't do very well in ponds that don't contain good amounts of vegetation as they end up mostly being bass food from lack of a place to hide. My hopes are I have just enough vegetation that a few brood fish survive, but that most of the little ones get turned into bass food. I would say the fish in those photos are 5 or 6 years old. But like anything, it really depends on the body of water they come from. If anything I think there are better odds they will be eaten into extinction than there is of them getting over populated. Chubsuckers are very new to the pond world, so the next few years will be lots of learning. Most will be going into my future SMB/RES/male BG and possible striper pond. A few will be stocked into my forage fish only pond. So we will see how they do...