Koi Fish 101: Koi Fish Care, Life Span, Diet & Breeding

| Published On:
Fishingery.com is supported by its audience. When you buy through links on our site, we may earn an affiliate commission. Learn More
What is a Koi Fish

Despite its name, the koi fish is a colorful variant of the ordinary carp. In actuality, the term “Koi” is just Japanese for “carp.” Thus, we call Koi a kind of carp known as Nishikigoi, which translates as “brocaded carp” in Japanese.

The koi fish has a regal history. Koi were first tamed in Eastern Asia in the early 400s as a source of food.

In the same way that farms today frequently produce chickens to supplement household meals, koi fish was formerly a staple of Eastern Asian homes. In reality, some people still consume koi fish.

However, the koi fish’s history has changed dramatically since then. Koi owners have bred over two dozen wide varieties of Koi.

As a result, Koi is a diverse and beautiful type of fish, ranging from the glittering Kinginrin to the traditional white-and-red Kohaku.

What Is Koi Fish?

The koi fish is a domesticated form of the common carp. This fish is mainly known for its stunning colors, which were achieved via careful breeding.

There are about 20 different types of koi fish, each with its own color, pattern, and scale type. The koi fish is native to Eastern Asia. This fish is found only in freshwater.

Image of different types of koi fish

However, Koi fish may be found in ponds worldwide due to their beauty and growing popularity over the last century. Koi fish are not on the endangered species list since they are plentiful and raised in private aquacultures.

Habitat

Wild Koi are endemic to freshwater bodies of water around the Black, Caspian, and Aral Seas. Carp were domesticated in the nineteenth century and are now found all over the planet.

Reproduction and development

Koi will travel long distances to reach their preferred spawning sites, including flooded meadows and stagnant marshy regions. The breeding season occurs in the spring, usually around May or June.

Females reproduce for the first time between the ages of 4 and 6 years, and males between 3 to 5 years of age.

They will reproduce every year after they achieve sexual maturity. They adhere their adhesive eggs to water plants or any other item that is submerged in water. The larvae hatch and remain in warm, shallow flooded regions until large enough to go into more open rivers.

Related reading: Walleye 101: Fishing Tips, Biography & How To Identify Them?

Koi Fish Facts

  • The Koi is a big fish. It may grow to be up to 3 feet long. Its living circumstances determine the size of the fish. A sufficient supply of food and oxygen and a suitable temperature are required for fish development.
  • The color of the koi fish varies depending on the type. They might be white, black, blue, red, cream, or yellow. Different spots cover the koi fish.
  • In Japan, koi fish represent riches, prosperity, love, a successful profession, and good fortune. Each variation is linked to one of these values.
  • Koi and goldfish are descended from the same progenitor. Despite their similar look, koi fish may be distinguished by barbels on the top lip.
  • The koi fish is omnivorous (consumes both plants and animals). It feeds on several types of fish and their eggs and lettuce, melons, and peas.
  • Koi fish can know who feeds them and can be trained to eat from their hand.
  • Raccoons, otters, badgers, birds of prey, snakes, cats, and dogs are among the predators of koi fish.
  • Koi enjoy water temperatures ranging from 15 to 25 degrees Celsius. It is not tolerant to extreme or fast temperature fluctuations.
  • Koi fish that reside in temperate climates hibernate in the winter. It swims to the pond’s bottom (which has warmer water) and lays inactive until the weather improves.
  • The sun causes sensitivity in koi fish. They may face sunburn if they reside in ponds with little shade.
  • Ammonia is released into the water by koi fish. When many koi fish live in the same pond, the quantity of ammonia in the water can quickly rise and cause fish poisoning.
  • Even though life in a community might be difficult, koi fish love the companionship of other koi fish.
  • During the mating season, the female produces hundreds of eggs fertilized in the water by the male’s sperm. Only half of the fertilized eggs will survive.
  • Because they are closely related, Koi and goldfish can mate. They do, however, have infertile offspring.
  • Koi fish often live between 25 to 30 years. Koi fish may live for more than 100 years if kept in ideal circumstances.

What Do Koi Fish Eat?

You can feed Koi nearly everything that humans consume. Shrimp, fruit, vegetables, and anything low in carbs fall into this category. Bread and similar items are difficult for koi fish to digest. You may also provide them with fish meal pellets.

Spirulina Algae:

These blue-green algae, also known as cyanobacterium, live in water and produce their nourishment. They are incredibly tiny, only reaching a length of half a millimeter.

image of Spirulina Algae in a bowl

This algae floats freely and can be found in lakes with exceptionally high pH and hard water. Feed spirulina algae to koi fish for the following benefits:

  • Increased growth rate.
  • Improved digestion.
  • Boosted immune system.
  • Aiding in the prevention of swollen abdomens.
  • Enhancing the production of particular enzymes that break down fats into energy.
  • Bringing out better coloration due to carotene pigments found in the algae.

Wheat Germ:

Wheat germ is excellent for feeding koi fish. Don’t worry; it’s not a nasty germ. Instead, this portion of the wheat sprouts and develops into a new plant referred to as the wheat seed.

Image of Wheat Germ

Wheat germ has been demonstrated in studies to help goldfish and Koi develop quicker. It is also a natural source of vitamin E, which enhances blood circulation, boosts oxygen and nutrient flow, promotes healthy growth, and aids in illness prevention.

Brine Shrimp:

Here’s a scientific term for you: bio-enrichment. Brine shrimp filter water by consuming anything they can find, which isn’t much due to their small size.

The nutrients they consume are passed on to the fish that consume them, a process known as bio-enrichment. Brine shrimp are very beneficial for feeding newly born koi fish.

Fish Food:

Pellets are best for medium-sized Koi, whereas bars of fish food are best for bigger Koi. Most include a high protein content, a minimal amount of fat, and essential vitamins and minerals. Worms, larvae, tadpoles, shrimp, and clams are also popular.

What Is The Average Lifespan Of A Koi Fish?

How long do Koi live?” Let us clarify this statement.

Koi fish have three lifetime ranges: those managed in optimal conditions, with optimum water quality, pH levels, nutritional health, and minimal stress, may live into their 50s, 60s, and even 90s.

There are rare outliers, such as Hanako, who supposedly lived to the age of 226!

image of oldest koi fish

Koi fish managed by inexperienced fish keepers live considerably shorter lives. For example, 3-5 years since the proprietors may lack vital understanding in the activity. As a result, the lifespans of these Koi have been decreased.

Koi fish are more likely to survive longer than 25 years in the hands of most Koi collectors. You may be perplexed by the large disparity, considering that it is still a small distance.

This is because most Koi outlast their owners and rely on others for optimal circumstances and maintenance. Unfortunately, people eventually lose discipline when it comes to pond care, leading to the fish’s death or decreasing their lifetime.

Can You Eat Koi?

You might be keen to know what Koi tastes like for yourself! Such a colossal fish must taste like something out of this planet, right? After all, Koi were historically grown and kept for food, as previously stated!

Since then, mankind’s connection with this fish has evolved and expanded dramatically, and it is no longer consumed as freely as it once was.

image of a person cutting the Koi fish
@RAWWFishing

Having said that, Koi may still be found on menus and in home kitchens in Thai and Bengali cuisine and areas of Europe.

Koi and other carp have a negative image of palatability in the United States since they are regarded as ugly invasive species that are predominantly bottom-feeders, leading to prejudice that they are low-quality fish with low-quality diets.

If you are traveling in a foreign country and want to taste the local food as part of the cultural experience, you might be interested in sampling koi fish.

Trying something new may be a rewarding learning experience that allows you to understand more about a culture and its history via your taste sensations.

If you tried eating Koi, you would probably get approximately the same nutritional value as eating most other fish species. Its nutritional content would be closest to that of a common carp, their immediate natural progenitor.

What Do Koi Symbolize?

Have you ever wondered why there is so much koi imagery in tattoo art, interior design, sculpture, and painting?

Koi are colorful and attractive creatures, but their usage in art and design is typically symbolic rather than aesthetic.

Image of koi fish

In Asian culture, koi carp are adored and have numerous symbolic connotations. It’s not difficult to see why if you look at the history of Koi, their characteristics, and the tales that surround them.

Symbolic Meanings:

It should be no surprise that Koi are frequently linked with character strength, persistence, success, and courage. The fish also represents luck, success, prosperity, and ambition.

Koi are also linked with longevity due to their long history and resilient nature. In other terms, Koi represents everything good. Koi of different colors each have their own meaning.

  • Kohaku — a white-bodied koi with red markings that represent professional achievement.
  • Kumonryu – is a koi with a white body with black spots or an all-black body representing life changes.
  • Ogon – is a silver-colored koi that signifies economic success and prosperity.
  • Kuchibeni – is a white and red striped koi with crimson around its mouth, representing love and long-term partnerships.
  • Yamabuki — a gold-colored koi that symbolizes prosperity.

How To Catch Koi?

Empty And Scoop:

The simplest approach is to drain the pond until there are just a few inches of water remaining. If you want to drain the pond, you can choose any tight mesh net.

You don’t have to utilize landing nets from a sports goods store. That sort of net has an inch grid, and the Koi’s fins and scales will get caught in it, ripping them off.

Instead, purchase a net with a much smaller mesh, like 1/4″ holes. Catching Koi in a wholly stocked backyard pond is a lot tougher than it seems on youtube videos.

image of a person catching fish with net

After years of effort, you can eventually learn how to do it and choose one Koi out of an entire pond relatively simply. You’ll need a good koi net for this. They have a huge diameter but a reasonably shallow depth.

Picking Up, Holding, And Carrying Koi:

Koi are large fish with weak bones, so you have to be careful. When you net the Koi, there is a unique technique for lifting and carrying Koi by hand. It does a pretty good job of showing how to handle small Koi.

For smaller Koi, you place one hand under their head, the other hand under their anal vent. It may sound weird, but the problem is that Koi will remain motionless for a short period of time before abruptly jerking up and flipping their tail.

image of a person picking up the koi fish

If you don’t hold them properly, they will break out of your grip and fall to the ground, maybe breaking their back. The video also shows the process of putting a plastic tub underneath them while in the water, then lifting the container and fishing out together.

For larger Koi, such as those in the 24″ and larger sizes, tuck the Koi’s head closer to your armpit; larger Koi will do greater jerks to attempt to get free, and you’ll need a better grasp on them.

Using A Sock Net To Transport Koi:

A better approach is to utilize a sock net, which most experienced koi breeders use. It’s simply a short stick with a ring on one end and a cloth tube on the other. You may elevate the Koi by sliding the cloth tube (sock) over them.

However, when you arrive in the tank to place your Koi, they slide out the opposite side of the sock. As a result, the Koi can only go one way through the sock. If you try to return the Koi the same way they arrived, their fins will snag on the net and be injured.

And, like the bowl net mentioned above, every koi owner wants a sock net for managing their fish. Using one of these is just so much safer and easier.

Koi Species Identification

Shusui:

Japanese Koi Shusui Terms a dazzling blue blended with pale orange to a dark Brilliant Red. Shusui is a mixture of primarily blue, primarily orange, and any combination in between.

image of the shusui koi fish

Their color can range from a pale blue/white to a bright sky blue. In addition, the color ranges from pale orange to dark red. They should have a consistent pattern of pine cones down the back.

Because of their beauty, the Shusui with a vivid blue base and a dark crimson top are in high demand.

  • Ki Shusui – The orange is replaced with a yellow
  • Gin Rin Shusui – Sparkles are added

How to identify male and female Koi?

Koi are sexually dimorphic, which means that males and females appear and behave differently, but it’s not always easy to tell the difference.

They are similar in size and have colorful scales, but there are minor distinctions if you know where to look. With these hints, you’ll be able to decide whether to name your finned buddies Fred or Frieda.

Age:

Koi are simpler to distinguish when they’re grown, so your first indication will be their age – which is connected to their length.

When they’re around 10 inches long, they’re considered mature (3 years old). They’re still juveniles if they’re between 3 and 10 inches long and may be difficult to sex.

Body Shape:

Trap your Koi by catching it in a pond net and inspecting it from above. A mature male koi has a thin appearance, but a female koi has a rounder appearance, especially when it’s spawning season and she’s holding a nest full of eggs!

Fins shape:

Next, look at your Koi’s fins. The pectoral fins of a male koi, located near his head, will be pointed and solid in color. Furthermore, his pectoral fin’s initial ray may be larger than that of his female counterpart, who will have rounder fins.

Tubercles:

You may see little white growths on male koi’ heads and pectoral fins during the breeding season, known as tubercles. They’re completely natural and will vanish after the fish have finished being frisky. These protrusions do not grow in females.

Koi Fishing Tips

A good rule of thumb is to remember that Koi are members of the carp family; therefore, you should use methods similar to those used to catch other carp species. Consider the following:

Clear Fishing Line:

Because Koi are intelligent fish, you should always use an obvious line while fishing with them. Unfortunately, like their carp cousins, they can detect colorful fishing lines, which frightens them and causes them to flee.

image of a clear fishing line reel

Of course, you may use a braided line if you want something lightweight, but keep in mind that it must have a fluorocarbon or other transparent leader on it if you wish the Koi to bite it.

Use A Thin Line:

You could also consider using a light line for koi fishing since it will allow you to feel the tug on your line when a koi eventually hits.

Koi, like other carp, have a propensity to slurp on the line, making it difficult to feel the bite unless you are an experienced angler. Furthermore, using a light line allows you to cast your tiny bait considerably further out than usual.

image of a clear white fishing line spool

Even if you manage to land a giant koi, they, like all other members of the carp family, have a smaller mouth. So if you’re fishing for smaller Koi, you can probably get away with a six-pound line or less.

Use Baits:

Another factor to consider is locating the finest bait for finding your Koi. While we know that catching Koi is entirely lawful in most countries, we still need to figure out what these small animals will eat.

Furthermore, understanding their behavior or the sort of line they may require would be useless if we did not have a complete grasp of the bait.

image of five fishing baits

Koi, like catfish and many other species, are bottom feeders. That is, they prefer to eat on the bottom of the river or stream they are in. Thus, while experimenting with different baits, you would be wise to select a bait that bottom feeders prefer.

Bucktail jigs, live insects, spinners, and anything that causes a dragging motion on the sand are all ideal baits to try to catch a koi with.

You might use many other leading tactics along the same lines, such as moss flies, algae flies, glow bug regions, or pellet flies. Many inexperienced koi anglers have had success with some of these techniques.

Final Verdict:

Koi are gentle, friendly fish who like to live in couples or groups. When deciding whether to add a new fish to an existing habitat, always ensure that their environmental and nutritional needs are the same as the present fish.

When adding a koi fish to an existing pond, ensure that the pond is large enough to sustain a full-grown koi.

As incredible as it is that some koi fish may outlive their owners, with some reaching their 50th birthday in captivity, the responsibility that comes with keeping a koi fish is much greater!

All you need to do to give your pet koi fish a long, healthy, and happy life is satisfy its basic tank requirements and feed it well-balanced food. Koi Fish are as beautiful as they are large, yet they are the simplest aquarium fish to care for in their size group!

Frequently Asked Questions

#1 – Why are koi fish so special?

Koi are a kind of carp, a common fish found worldwide, but what distinguishes them is their coloration and ancestry.

As a result, there are frequent competitions to name the best Koi, and Japanese people take koi breeding extremely seriously, just as they do treasured dog breeds.

#2 – Are Koi illegal in Australia?

Koi can be sold or taken out of the nation; however, bringing Koi into Australia is banned.

Even though Koi may only be kept in New South Wales and Western Australia, the Australian Koi Association has around 230 members.

In addition, other state government fisheries bureaus have outright prohibited Koi.

#3 – Can Koi fish be eaten?

Anglers agree that Koi are edible since people all around the world consume carp. Koi are Amur carp that have been selectively bred for their distinct color, and carp, despite their poor reputation as table fare, may be tasty.

#4 – How much does a koi fish cost?

Generally, pond-quality koi range in price from $10 to $100, depending on size. Show-quality koi are on the other end of the range.

The best are breeder certified, which means they have very stable bloodlines (genes) with a high likelihood of passing on their primary color features.

#5 – Are black Koi rare?

For a long time, Karasugoi has been the sole true black-colored Koi bred by Japanese breeders. They were formerly relatively unknown in the western world. This koi species is available for purchase in a variety of locations.

#6 – Can koi fish be kept in a fish tank?

Young Koi can be housed inside an aquarium with a capacity of at least 29 gallons. Place the aquarium in a calm location away from direct sunlight and draughts.

When transferring young Koi to the aquarium, float them in the water within their bag for around 10 minutes to acclimatize them to the new water temperature.

#7 – Are koi ponds high maintenance?

A koi pond does not have to be high maintenance, but it does need to be maintained regularly to preserve the health of the koi fish you keep and the plant life you choose to decorate within and around the pond.

#8 – Why do koi fish have tattoos?

Perseverance is the most prevalent meaning of koi fish tattoos. They are frequently used to represent personal challenges that one has conquered or is conquering. Other meanings can be added based on the tattoo’s colors and design.

#9 – Do koi fish recognize their owners?

Koi Fish remember their owners, mainly when the person feeds them regularly. Koi fish are very clever and can even recognize their own names if their owner spends enough time with them to earn confidence.

#10 – How much is a full-grown koi fish worth?

The average price of most koi fish is around $50, although it can go much more (many thousands of dollars).

This price fluctuates depending on a variety of factors, including the genetic ancestry of the specific Fish (Fish from a highly valued genetic line are much more expensive)

Your Author

  • Since 2009 I've been writing on different media portals about fishing. Here on this website, it's time to share those experiences I've witnessed in my entire life so far. Let me help you get the best stuff you need while fishing.

Leave a Comment