What Do Baby Koi Fish Look Like? (Pictures & Video)
by Tory Jon | Last Updated: June 14, 2021
The first thing people think when they hear the word "koi" is that of a beautiful, colorful fish.
And while this may be true for adults, it's a different story for baby koi fish.
So, let's take a quick look at some pictures of baby koi (and video), learn more about their color at this age, as well as some other koi fry facts!
What Do Baby Koi Look Like?
Baby koi, also referred to as koi fry, look like a smaller version of an adult koi fish without the bright, beautiful colors that koi are known for.
Baby koi fish are largely absent of color or sometimes even brown in color. You may even see the trademark red or orange color on koi fish fry, though it won't be as bright or defined as it will be when it reaches adulthood.
Did you know...
Some believe their lack of color is a genetic trait designed to protect them from predators.
With that said, let's back it up a bit...
When koi fish eggs hatch (see what koi eggs look like), the koi fry are so tiny you can barely see them in the water. In fact, you might not even notice them swimming around your koi pond for the first few weeks.
But, that changes rapidly...
Koi grow extremely fast, feeding off first the yolk of their egg, then off algae and other organisms in your pond. By the time they are around one month old, they are already an inch long.
After 2 to 3 months, they can be up to 3 inches long! Over the next four years, young koi carp will continue to grow until they reach their full adult size of 24 plus inches.
In this video, you can follow the process of adult koi spawning eggs, the baby koi hatching, and the growth of the baby koi over several months.
Learn more about how fast koi grow and check out our koi growth chart in that guide for a visual representation.
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When Do Baby Koi Get Their Color?
Baby koi will start to get their color after only a few weeks. The coloring will deepen and become more obvious after 2 to 3 months and will continue to change and develop as they grow.
With that said, coloration will vary wildly based on their genetics, type, and many other factors. For example, I've seen 1-year-old koi that are still brown.
Keep in mind, even the best koi breeders only keep a portion of the fry as some will never develop the bold, beautiful colors that koi owners are after.
How Can You Tell if a Baby Koi Is a Goldfish?
If you stock both koi and goldfish in your pond, you can tell if the baby fish are koi or goldfish by their color. Goldfish are born completely black and will remain that way until they are about an inch to an inch and a half in length.
Identifying baby koi is just as easy. They can be pretty much any color that koi are typically known for (just not as defined as an adult koi), but they won't be black. Some varieties of koi are bred to be all black, but unless you stock all black koi in your pond, it's very unlikely to have all-black babies.
Again, the color of koi will depend on their age and will change and develop over time, but only in certain circumstances will they be all black like a baby goldfish.
