[MikeM]

This morning (Monday) my koi were spawning when I went out to feed them. There were 8 females being chased by 3 males. Four koi were not participating. They were eating roe.

I am not happy they were spawning, but I think it explained behaviors I observed on Saturday and Sunday.

On Saturday I observed a female swimming at great speed around the pond, not in a single spurt of energy, but as if racing against a clock. After three or so circuits of the pond, she came to a complete rest. [This was before I did the weekly 20+% water change.] The other fish got out of her way, but otherwise ignored her...this was strange. Normally odd behaviors results in schooling. Later in the day, I saw her do it again, but only for a single circuit around the pond. I was getting concerned, but at feeding time she was fine...a complete glutton; and the other koi were swimming with her. No isolating behavior.

Another female on Saturday flashed a couple of times, but not by rubbing her gill plate area against anything. She rubbed the side of her body against the pond wall. Since nothing more occurred, I decided not to disturb her, but to stay alert.

On Sunday all the koi were ravenous. At their morning feeding, they consumed over 150% of what they have been eating lately... and I was feeding the same pellets they have been getting for the past month. At midday they rushed to me to be fed...very unusual behavior. I had just picked up a new high protein pellet, so I tossed them some. They ate with gusto. At the same time, I saw two other females "flashing" by rubbing their flanks against the side wall of the pond a distance of a couple of feet... not the "quick scratch" you usually see. I became convinced there was likely some parasite problem. I had to leave to go to a club meeting, and decided I'd address the situation later. Sunday evening, they were still eating with gusto, charging the surface for pellets...but not a single instance of flashing. As the sun was setting, I emptied settlement and put in some fresh water as I do every evening. I then observed several "flashing" against the side walls, but it was getting too dark to do anything. [I never treat for parasites etc without being confident exactly what is occurring.]

As I worried over the flashing Sunday night, I recalled three years ago when my oldest koi was flashing against the side walls of my old pond, not the bottom, and that she spawned shortly afterward. I got a sample of pond water and ran my usual array of tests...nothing. Everything was normal.

This morning, the flock was spawning.

This evening I observed one female had lost all her bulk. Another was notably thinner, but still has eggs. The others did not seem to have lost much bulk if any. Their evening meal was limited to the eggs scattered every where. There are even hundreds of eggs attached to the inside of the skimmer. I saw the three largest females "flashing" against the pond wall again. I'm expecting more spawning in the morning.

I'm interested in whether others have observed like pre-spawning behaviors. I think it is interesting that the females are initiating the spawning.