A lot of good reasons in this thread in regard to why fishkeepers dont keep natives. one thing not touched on is when a non native species gets introduced into local waterways. most tropical fish won't survive in most of the US. snakeheads obv can and managed to establish themselves and impact the native species and have since become illegal. The northern pike is an example of a northern midwest native fish introduced and established in non native California waterways. i'm sure most of us here wouldnt release a fish into a local lake. but there are people out there that do.