Just a small update. They need to be pretty large before they are sexually mature. Conferring with a friend who is raising some they are already 4ft and close to maturity. He has lost some and only has 3 left. They are looking pretty healthy but he does not have a good idea on the sex yet. They grow extremely fast, at 6 months old they were over one foot long. They are just over 2 years old now and should become mature soon. Maybe next year they will start to breed.
I know someone else who is trying to bring some more in and raise them up in very large ponds, like 1/2acre to 1 acre ponds.