it could have been in the pond since it was a juvenile...
say i take a gar from the time it is a fry...feed it feeder fish, and let it go once its big enough to fend for itself...it would survive...almost as if you just raised it...and set it free...
i agree that noone should let a fully grown goldfish go in a lake...but there is no way to tell how long the fish has been there....some kid might have had it when it was just a little guy..and the parents got tired of hearing about it, and dropped it off in the lake...then it spent its entire life in that lake...and now your going to remove it from the habitat its grown to know?
It is not in a lake. It is in a creek that feeds into the Susquehanna River.