First off, I have Clown Knife. Second, I have guppies who LOVE to reproduce, they all are feeder guppies, but got to big for my clown knife to eat. Now, I have to buy less feeder guppies for him to eat because they are always having fry. I also have to emphasize the size they can grow to. They can grow up to 26 inches or so. I have had mine for a year now and it is 9 inchesish