The First Koi Spawn: Lessons Learned

We simply love koi. We have had a large koi pond for several years and also own two smaller ponds. Koi provide an amazing array of color and life for such ponds, making them especially interesting all year-round. However, we have never tried to encourage them to breed through natural spawning, instead we have always been content to just leave them alonge, aside from the occasional feeding and water change.

However, this year was different. We decided to try and get them to spawn, partly due to the fact that at least two of the female koi were absolutely plump with eggs. Thus, we did some research, both online and in print books. It was suggested to buy some sort of spawning medium, be it mesh matting, yarn or water plants, for the fish to lay their eggs on. One suggested plant was the popular water hyacinth. We purchased $20 worth of them (about 12 of them) and placed them in our main pond.

Sure enough, the addition of such spawning medium quickly encouraged the koi to spawn. Within a day of placing the plants in the water, the male koi were aggressively pursuing the female koi, splashing loudly in the pond. Within a few hours, the deed was done, and I noticed this by the large amount of water splashed on the side rocks, and by the fact that the koi were not creating a ruckus anymore. So, I carefully made my way to the shore and inspected the water hyacinth. Sure enough, all of them were covered with small, gelatinous balls, similar to the "Masago" sold on California Rolls at sushi eateries. However, here is where we ran into our first issue. How was one to know if these were eggs or just something we hadn't noticed earlier in the plants? I did a lot of research online, and the only pictures I could find of 'koi eggs' were blurry or indistinct. Very disappointing! However, we had placed one of our plants in a pond with only baby koi, so I checked it-no small eggs. Thus, I could safely assume these were truly eggs on the plants in the main pond and I took several photographs (see side bar) of the eggs, hopefully these will be of help to other koi enthusiasts.

The koi quickly began to suck on the water hyacinths, eating their own progeny. We moved all of the plants to the small ponds, but not before the koi ate about 25% of the eggs. Supposedly, the eggs will hatch in three days, but I have yet to see the eggs disappear-they're still there, some have some white mold on them (gross, but I read that this often happens) but a few appear to be larger than before and have some creature inside them (a teensy koi!).

Breeding koi can be a very strenuous job, for the koi and for you. The koi will appear sluggish and weak afterwards, at least from our experience and the plants or other spawning material must be moved to safety immediately after the spawning. Thus, koi owners have to constantly be on the lookout for the eggs, not an easy job if you don't work at a koi place 100% of the time. Finally, it is vital that you have a proper place to put the material with the eggs after the spawn, with proper water quality. I think that may be one of the reasons our eggs are not doing as good as they should be. It's exciting to think of having 100s of new baby koi for free, but raising them is not an easy job, so koi breeder beware!