I have heard stories about things that breed like rabbits but feel sorry for anyone who has something breeding that slowly. Show me something that breeds like endlers and you might have a prolific animal. Endlers drop fry on average every 23 days and they seldom prey on their fry. Without a predator, you could easily end up with very high numbers. I even have some endlers sharing a 10 gallon tank with a male Betta splendens and they are managing to increase their numbers with him preying on the fry.