When Do Koi Fry Start to Get Their Whiskers?

Whiskers, or ‘barbels,’ are one of the defining characteristics on a koi fish that make it easy to distinguish koi from their cousins, the goldfish. Otherwise, to the untrained eye, young goldfish and koi are difficult to tell apart.

When do koi fry start to get their whiskers? Koi fry whiskers develop almost immediately, though they may be so fine and small that they are difficult to see that early. As koi grow, so will their barbels.

When Do Koi Fry Start to Get Their Whiskers?-As Eggs
Koi Eggs

These slender, wispy bits of anatomy are not hair at all, but taste bud-covered organs that help a koi find food in the water. Barbels are important to a koi. And they’re important to koi fans as one of the ways to determine which kind of young fish is swimming in the pond. Want to learn more?

What Is a Barbel, Exactly?

The word barbel comes from the Latin word barbula, which means “little beard.” The little feelers on koi sit right on either side of the mouth or chin and do have the appearance of a fleshy, fish Fu Manchu. Although they look a bit odd, these mustache-like appendages come in handy for a bottom-feeder like a koi.

Bottom feeder? Yes. While a koi may be a fancy carp, it is still a carp, nonetheless. And it’s a bottom feeder. Especially in the wild, koi find their way to food’s general vicinity using their sense of smell. Once they reach the area, they use their fleshy, fingerlike barbels to scope out exactly where the food is hiding in the murky waters and sediment at the bottom of the water’s floor.

Koi typically have two sets of barbels: one set on the upper lip and the other at the corner of the mouth. They are controlled by muscles inside the mouth. If a koi’s barbels get broken, there is a very good chance they’ll grow back if the fish is in healthy water.

Telling a Baby Goldfish from a Koi Fry

If you have both goldfish and koi in your pond and you wake up to fish eggs in the water, you’ll have to watch them closely to determine what type of fish you have unknowingly bred! Fortunately, many of the defining characteristics of a koi are present at birth.

Characteristics of Young Goldfish and Koi

CharacteristicKoi FryBaby Goldfish
ColoringBorn with colors that will change/deepen/develop over timeBorn silver, gray or black and gradually develop color, starting on their back
Body ShapeNarrow bodied
Wider, more egg-shaped
Tail Style
Connected, whole

How a Koi Fry Gets Started

Once a koi egg is fertilized, it will cling to the nearest structure, such as the side of the pond or on pond plants. With thousands of its closest friends. According to ScienceLearn.org, A mature female can produce about 50,000 eggs per 1 lb. of body weight. And the average adult female is 15 in. long and weighs nearly 1.5 lbs. There will be a lot of eggs. But not all will survive.

The egg will stay attached to whatever it’s clinging to for a few days before hatching. Once hatched, it will drop to the bottom of the tank or pond. And now it is a koi fry.

What Does a Koi Fry Eat?

Baby koi are tiny, measuring just an inch or two in length. In the first few days of their life, they lived off the yolk sack from their eggs. Once they’ve dropped, they’ll continue to survive by finding bite-sized organisms in the water around them. If you are raising them in a pond or tank, you’ll have to help them along. A young koi needs protein.

Here are a few things you can feed them:

  • Hard-boiled egg yolk, crushed into a very fine powder and sprinkled in the water
  • Commercial fish food like baby brine and powdered food

Tips: Baby koi will need to be fed several times a day. And you may want to separate them from bigger fish until they are larger. When they are small, they are often considered food themselves by other fish.

Growth Cycle of a Koi

In the first year of life, the fry will triple in size to about 6 inches or longer. In the next two years, it will reach a typical adult size of 10 to 12 inches long. If they have a good environment and enough room to grow, they will keep growing every year. Depending on their breed, they may grow up to 36 inches long.

Maintaining a Healthy Environment for Your Koi

Your koi may start out as small, but keep in mind they’ll grow quite large, quite fast. For every adult koi you’ll keep, you’ll need 10 gallons of water for every 1 inch of fish. With a koi’s potential to grow up to 24 inches long or more, that means you’ll need 1,000 gallons for every four fish you raise. That’s a pond of about 6 feet wide by 8 feet long.

Once your pond size and water volume are in line with the amount of koi you keep in it, there are other considerations to keep the underwater environment a healthy place for your fish. This involves some very regular maintenance every day and all year long. You’ll need the right equipment and regimen in place to get started.

Regular Maintenance for Your Koi Pond


Keep your water clean.

  • Plants around your pond

  • Pump and filtration system

  • Bottom drain

  • UV sterilizer

  • A long-handled net, skimmer

Maintain a proper temperature – 59-77°F

  • Temperature gauge

  • Aquatic heater

  • Aerator or fountain

  • Plants around your pond

  • Heater and De-icer for the winter

Keep oxygen levels healthy.

  • Aerator or fountain

  • Plants around your pond

Keep predators away.

  • A fence or pond-netting

  • A “predator statue”

  • Motion sensor


The Long Lifespan of a Koi

With a healthy environment and good overall health, koi usually live 35 years or more. Some koi in captivity have lived to be more than 200 years old.

These exotic creatures live long lives and require daily care. It’s good to research koi and their needs before you bring them home. But once you’re sure that you are ready for the commitment, keeping koi can be very rewarding.

Koi ponds are often thought of as a meditative and peaceful place. A destination for relaxation and reflection. Watching the graceful movements of koi and listening to the sounds of the water are benefits many people enjoy from their koi pond.

Are Koi Expensive to Keep? Koi fish can be very expensive. Before you even head to a shop or breeder, you need the right habitat. An outdoor pond isn’t as simple as a pile of rocks. According to HGTV, the cost of a pond can easily range from $1,000 to $7,000, depending on who does the work and exactly how you do it.

The price of your koi can be anywhere from $10 to more than $1,000 each, as choices range from common varieties at the pet shop to fancier types available only from breeders. Cost also depends on how large the koi is and even how old it is.

Special Koi breeds are usually classified by specific colors, patterns and body shape. None of these traits are by accident. Many Koi are very carefully bred for certain characteristics and qualities, from physical appearance to their gracefulness in the water.

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Adam from Phoenix, Arizona, USA [CC BY-SA 2.0 (https://creativecommons.org/licenses/by-sa/2.0)] with modification

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