Spring has come and gone. It is now officially Summer. Your koi are responding to the warmth and the increase of food. And all the little fishy hormones and instincts that summer and spawning bring out. If you haven’t witnessed a spawning yet, you’ve either been out of the house at the wrong time or your fish are still too young. All it takes is one well fed female older than 18 months to set the whole thrashing, racing, excitement off. The males chase her, bump against her to get her to spill her eggs. She circles looking for a place to deposit the eggs, a place where there is enough vegetation for the eggs to attach- hyacinth roots, hair algae, water lily stems, anything hanging down into the pond like a formal spawning mop.
After her race the entire pond. The excited males ready to bring those eggs to life, and the rest of the pond, hungry for caviar for lunch.
When conditions are right, and That is frequently every time, many of that spill of 250, 000 eggs will go uneaten. About half will hatch. And in 3 days those fry will be free swimming.
A professional breeder will have separated the female and her courting males from the rest of the gang. And once she is through laying her eggs, he will scoop the female and the males out, leaving the eggs alone in the breeding pool. He will have allowed the pond to have turned pea soup green with algae-- protecting the eggs from predators, moderating the pond temperature, providing a high oxygen content during the day to the water. Of course the foam and milt from the males will have also contributed to the bloom of algae.
But we’re backyard guys. And now our job begins with those hatching fry. The pump has to be turned down so the tiny fry don’t get sucked in. The pond population won’t eat the fry once they are free swimming, but we need to protect the eggs until they hatch. Unfertilized eggs are susceptible to a fungus growth which will spread to the fertilized eggs if a sharp eye is not kept on them.
At first the fry will consume the pea soup algae. And then koi food -- but koi food ground to a powder at first. The pump may be turned down, but the filter needs to work twice as hard to clean the water from not only the powdered food, but also the enormous load of fish.
So a professional now culls.
Which any backyard breeder, any serious backyard breeder needs to do. Both to ease the load on the filter and to keep the bloodlines healthy. Out go the babies with deformities-- missing fins, crooked backs, strange mouths. And then another cull for pattern. You want kohaku? Keep the red fish, pitch the black. You want platinums, keep the white fish, pitch the red and black. Red is quick to develop, black is slow, so any fish with much black is likely to remain black.
Culling is frequently the hardest part of raising those quarter million hatched fry. And a professional culls the first cull at one eighth of an inch for the first cull.
At work one day, long before I got into stocking a pond, someone talked about how excited he was at buying a home with a koi pond and how much money he was going to be able to make from raising koi. It seemed at the time a little simplistic to think “Koi equals Big Bucks.” Any backyard breeder can tell you it takes considerably more time and effort to find that one perfect fish. from a spawn.
Or even that one perfect fish at a dealer, for that matter.
Enjoy your babies’ summertime romp. But keep in mind just how much their X rated fun is going to cost you.