Ready to Spawn?
It is soon time to spawn again, and among koi keepers that is seldom a planned affair. Before you know it, one morning your wake to a strange smell and wondrous sight as your prized collection "suddenly" decide to spawn en masse. Then it is mostly to late...
When the temperature stabilizes to above 18°C you know that given time, spawning will happen so best isolate the one female and one male you want to breed with and keep it plain and simple. Yes, I said ONE male and ONE female. Why on earth would you want to use more? On the average property you cannot hope to raise the fry of one female, why more? Managing your spawn time I’ll try to describe in a follow-up article. In the mean time prepare yourself well in time for the important event: You don’t want an unplanned encounter.
Having a good high protein fish food to start the babies on is one on the things you should plan on. Get hold of a high protein (more than 40%) feeding formula. The growth rate of young koi and goldfish is high and they have a requirement for a diet with a higher level of balanced amino acids than older, larger fish. This is because they are growing muscle at a high rate.
Just “throwing protein” at the fry is not enough. Trout, eel and tilapia will “work” but are just not adequate. Even carp starter diet does not provide for the much needed natural colorants ornamental fish require. They need the colorants to ensure the maximum uptake of these by the developing chromatophores. Penny wise leads to pound foolish and koi farmers is nou exception.
Not all fry are born equal and not all fry hatch at the same time. This translates to different sized mouths to feed. If the fry cannot find the right sized food, they will starve, cease to grow and ultimately die.
Clandocera, a crustacean, is the favorite feed of the newborn larva. It is a wide-ranging order of microscopic water life often called water flies (daphnia) ranging in size 0.2 - 6 mm though they seldom get the opportunity to grow that big. Farmers culture these by preparing their fry ponds in advance because the newborn will only hunt for living organisms, and the baby daphnia happens to be the right size. Poor thing. Yes even if you do not know it there is microscopic life that is exploited by the fry in the beginning. Some will survive and grow.
But the supply of Clandocera is soon all eaten by the hungry fry so common practice is you replenish it from a culture you have on the side, or switch to Artemia (brine shrimp) another Crustacea of the same order, that can handily by raised from eggs on demand by the farmer and in fed in regular doses.
A shortage of food for the fry will simply mean that the bigger fry will eat more and bigger Clandocera, leaving their siblings behind in growth. The hunger, larger fry will even turn onto their own siblings to eat. So having enough food of the right size is vital for a good healthy crop of fry of much the same size. This is then the time (about 5-8 days of age) to slowly wean them of live food to ensure their growth and development continues at the supposed rate. (1 mm/day minimum) The strategy you employ to do this is crucial for a return: eggs in versus juveniles out.
And this is where high protein formula is so handy. The farmer can offer the food in various forms and bridge the gap from larval to post-larval stages to juveniles for first culling.
The aim is to have have the fry at the right size at the right time for their first culling. And that is a function for the variety you are spawning. And that is why mass spawning or crossing incompatible varieties should no be attempted. You will just not know what to cull for and when.
Your aim: You want to cull Sanke at 30 days and they should be 25-35mm. Kohaku at 40 days, about 35-40mm, Showa and Shiro at 3-4 days.
That is to give the best koi the best chance as the beginning of their life.
Servaas de Kock
What about using chicken egg everyone is talking about?
More on preparing yourself for the great day.
Note: Almost all the breeders in Japan offer the probiotic Miracle Animal to their fry food. There must be a reason.