I am pretty sure they are native. I had one in a tank for a few years. They are great fish and good hunters. Mine would eat anything I dropped in the tank. I gave him a garden slug (100% meat) one time. He kept spitting it out to get rid of the slime but he never gave up. When the slug was all out of slime, he swallowed it and was happy about it. (you have to be careful what kind of slugs you feed them though.)