I have large koi around 25/26 inches and 7 to 8 years old and never have seen little ones. All together there are 10 koi in the pond 1 gold fish and 1 shubunkin. Never any babies. What can be wrong they all can't be one sex. I don't know how to tell who is who but going by some of the books stating fin size and body size there should be 1 or 2 males and rest female. I have cattails and plants and plenty of rocks for them to hide in if ever they do breed but nothing so far. Suggestions?