just thought i'd mention, a friend of mine was getting "rid" of a moor a few years ago and had no where to put it, so we put it into our pond. We didn't think it would survive long but 3 years on its happily swimming around with the koi's and goldfish out in the garden and even survived the freezing winters. i don't think this is natural practice but we've had no problems with him. in fact, i think soon we'll have to put him on a diet!!!