Caring for koi fry is perhaps one of the most daunting things that comes with keeping the species. That being said, it does not have to be particularly challenging. Koi fry care is rather simple when if you go into it prepared and with a good base knowledge of what to expect. Let’s look over the main points of koi fry care!
The Absolute Basics of Koi Fry Care
So, when male and female koi mate, they produce a batch of eggs. Once these eggs are in the tank, you should remove the adult koi to prevent them from eating the fry when they hatch. Add in a fry nest to give the babies something to grab onto when they hatch, which should occur around four days after the eggs are laid.
In general, you should make the conditions in your fry tank or pond the same as those of the pond they will be introduced to. For starters, the temperature is vital in raising healthy koi. Both your regular pond and holding area should be kept at around 65 and 75 degrees Fahrenheit and remain at a relatively stable temperature in general. Koi can tolerate lower and higher levels but the fry are much more susceptible to being harmed so it is best to stay within this range.
The water should also be kept clean and there should be an added oxygen rock since they do not yet have gills or lungs and will not until a few days after birth. It should also be held at a steady pH to prevent shock and high ammonia levels within your pond, as well.
Feeding Koi Fry
When feeding koi fry, it is important to remember that frequent, small meals are key at first. In fact, you will not feed the koi fry at all until they are swimming around the pond a bit. This takes around four days or so.
When it is time to feed for the first time, try a liquid food or finely crush up fry koi food into powder to feed them. Their mouths are tiny, so be sure it is very fine. After a few weeks, you can move up to more solid, larger pieces. Keep increasing until they are up to normal pellets. Do expect this to take upwards of four months, as it is a very slow process to ensure no digestive issues.
Culling Koi Fry
Culling is a rather unfortunate aspect of keeping koi fry. While all of those babies are adorable and certainly fun to watch, it is not feasible to keep all of them. There is a massive amount and unless you have the capacity to professionally breed fish, your own personal pond cannot safely hold an entire batch of koi.
Generally, this means that you will have to cull some of the babies. In this process, fish keepers select fish with desirable traits and fish that seem overall health and keep them. The rest of the batch are either given away or humanely dispatched, depending on the preferred outcome.
This may seem awful and while it is certainly no fun at all and a very serious matter, culling koi is simply part of the process. If you allow all of the koi fry to reach maturity, the competition between the fish would be insane. They would have to fight for food and end up killing each other. It is best to thin the herd and create a well balanced, desirable batch of new koi fish.
Generally, three rounds of culling will be done and the entire batch of fish will be cut down by between one half or three fourths, if not even more steeply. You should only keep the healthiest fish to prevent bad genetics from being passed down.
When can I introduce my koi fry into the pond?
While it might be tempting to add the fry you chose to keep back into the pond as soon as possible, this is not a route that will provide good results. Koi fry are very, very delicate and can be harmed by the faster moving big fish or even eaten if they are small enough.
It can take up to six months for koi fry to become large enough to viably be introduced into a pond, especially if there are large goldfish sharing the space with the koi, as they tend to enjoy eating fry when they can.
Introducing the koi slowly will also help preserve their health in general. Ponds are slightly less controlled when compared to a holding area so your fry are more likely to contract illnesses or become sunburned or otherwise damaged.
When it is time to introduce your baby koi, be sure to do so gradually. Place them in bags and let them acclimate to the temperature of the pond and then gently add them in. Monitor them closely to ensure no scuffles occur with the larger fish and to double-check that they are not too small or at risk of being eaten. Koi are tough fish once they are developed so you do not have to worry about too much after the first couple of days; hang in there and everything will adjust and adapt in no time!
All About The Koi Babies
Koi fry are incredibly fun to raise and provide a very rewarding hobby. You get to literally watch them go from tiny eggs to actual fish in less than a year then have the pleasure of continuing to experience their growth as they develop coloration and patterns as they age. While initially daunting, raising koi fry is not as scary as it seems if you enter the hobby prepared and well-versed in the ins and outs of koi development.
All in all, if you are well researched and have a good setup, you have good chances of producing a wonderful batch of baby koi! Good luck!