"Q: I want to breed these fish, How do I sex them? Good question. If they are around 1.0-1.5 inches SVL.....good luck. These are juvenile animals and Iխ a full 50/50 at this size (meaning Iխ either 100% right or Iխ totally wrong). These fish become sexually mature around 10-14 months of age, and in my experience its almost impossible to visually sex them until they reach sexual maturity. However when they do become sexual mature, the best indication is a "squaring off" of the jawline (a more bulldog appearance) in male fish compared to females. The best overall indicator is the second dorsal or "banner" fin, it quite long in males, as compared to females, however it gets chewed off by other fish."