
Originally Posted by
Matt24
When it comes to male koi roughing up females, pond set-up matters significantly. I've found that most of that behavior can be prevented by not having water plants or much other material (fallen leaves, nets, etc) in the water for koi to lay eggs on, and certainly no sharp rocks to get scratched on. Even with this, amorous behavior happens anyway, but very rarely gets amped up (once in 17 years for my current pond).
But spawning is still possible. Our pond is very close to the house, so that if they get too splashy, we can hear them, and go remove the female that is sparking all the attention to a tub, where she may lay her eggs if she has gotten started. In the case mentioned above, it was a small female in a pond that included 15+ larger males, some much larger. So I had to rescue her.
Another factor is whether one is trying to compete in shows or not.
Prior to this current pond, I used to let them flock spawn, and in recent years, intentionally in a tub. I'm might be fortunate, but in 30+ years, I've seen females get exhausted and/or scuffed a little, but have never lost one during spawning.