As mentioned in Flowerhorn history, they are crossbreeding species. As a result, the majority or even most flowerhorn males are sterile, which means that they cannot reproduce. By far, a very small percent of a batch would result in fertile males whereas the rest of the batch or sterile. Since not every male flowerhorn is fertile, finding a best or perfect fertile flowerhorn is time consuming. That is, hobbyists have to wait until the fish is sexually mature and then pair the male with a female to see if the male is fertile. It takes up to 8 months for a male flowerhorn to be sexually mature. A recommended age for a flowerhorn male to be tested its fertility is 10 months. Note: The process of testing the male's fertility is the same as pairing and breeding fertile ones.
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