I can say without a doubt that mine have reproduced multiple times this season. My pond is now totally devoid of any vegetation that is in the water. This year the results have been more dramatic for me because we are in such a bad drought. I stocked more fish this year and have much less water because of a lack of rain. I know I was overly optamistic about our rain chances. Even though I have hybrid bass in my pond they can't keep up with the reproductive power of these fish. The way they can reproduce is amazing. I can see how they could very easily cause problems of overproducing.