Introducing an aquarium fish to the wild, wether native or non-native is a cardinal sin for a fishkeeper. Even wild caught native fish can pick up non-native disease in your tank that you could be unleashing upon the native ecological system. A non-native introduction is even worse. Non-native species compete with native fish for food and habitat, eat native fish eggs, and even destroy habitat all together. Non-native species that have caused significant problems include many species of carp, zebra mussels, the round goby, the spiny water flea, and species of snakeheads just to name a few. The introduction of snakeheads to native waters has caused the ban of ALL species of Channa to be banned from the United States. These beautiful monsters are no longer allowed to be kept in aquariums. There is also a sustained population of goldfish in the mississippi river and although they don't cause much of a problem, they give DNR officials ammo in trying to ban more species of fish that you and I keep. NEVER RELEASE YOUR FISH OR INVERTEBRATES INTO THE WILD. I hate to say it but euthanizing your fish is actually a better option than letting them go. I choose neither. If there is a fish I absolutely cannot keep anymore, I sell it or give it to another fish keeper that will provide a good home. I hope you will do the same.