Koi fish that have done something that hardly anyone else has done with their species, such as Hanako, who lived for 226 years, in 2018 S Legend Kohaku Koi was sold for the most expensive price, and then the big girl koi fish that has set a world record for being the largest koi fish.
This 4-foot koi fish is amazing. It was named Big Girl due to its large size. And its size is so big that it is three times bigger than a normal koi fish.
Apart from that, in this blog post, we will talk about the reasons why this big koi fish is so big and also how you can maximize the breeding potential of your koi fish in today’s.
How big can a Common Koi Fish Grow?
Common koi fish grow from 12 to 24 inches, but some rare large koi fish have been seen that set a precedent. Rarely, some can grow to 36 inches or more, but some unusual koi fish have exceeded 45 inches in length.
Reasons for the different growth of koi fish
Like domestic koi, which can usually grow to 12-18 inches.
Japanese koi can grow to over 24 inches.
And jumbo koi can grow to 30 to 36 inches.
The record-holding Big Girl koi which has a chance to grow to over 44 inches.
The good news for koi owners is that with good care and the right genetics, their growth can increase, and this has been proven by the world record-setting koi fish.
Biggest Koi Fish in the World: Ever recorded
In these few years, incredible things have been seen in these koi fish, due to which they have been able to make their own identity, such as an extraordinary increase in size, and some important facts about them are described below.
All these koi fish have some special things that you probably don’t know, so let’s find out.
1. Big Girl Koi
This koi is the longest koi fish ever recorded in the world, which makes it a giant koi.
| Important Points | Detail |
| Name | Big Girl |
| Species | Koi (Nishikigoi) |
| Length | 4 feet (48 inches) |
| Weight | 91 lbs (41 kg) |
| Origin | Japan |
| Owner | Geoff Lawton (UK) |
| Significance | Largest koi fish in the world |
| Lifespan | 25-50 years |
| Growth Conditions | Excellent diet, large pond, and top-quality care |
The reason for its growth is that it was given a large pond where it could feel free. Its daily routine includes excellent water conditions, high-protein food, and careful care.
This type of Chagoi is the only one that has grown itself and managed to set a world record. And it has made it clear that if a fish is given good care and water quality, then the chances of it growing increase.
2. A giant kohaku koi
which is capable of growing to a gigantic length of over 40 inches.
| Name | giant Kohaku koi |
| Size | 3 Feet 4 inches (40 inches) |
| Weight | 80 lbs (36.28 KG) |
| Owner | Sakai Fish Farm (Japan) |
| Origin | Japan |
| lifespan | 25 to 50 years |
| Diet for Growth | balanced diet of protein, vitamins, minerals, and carbohydrates. High-protein koi food, |
Yes, this is the same Sakai Fish Farm that is known for producing the most koi fish in the world and adapting to the best environment, and the most expensive fish was also from their farm.
And these farms pay special attention to selective breeding and exceptional care for koi fish.
3. Hanako the Oldest Koi
This koi fish lived for 226 years from 1751 to 1977, and this koi fish set a world record.
| Main points | Details |
| Name | Hanako (“Flower Child” in Japanese) |
| Species/Color | Scarlet koi (Cyprinus carpio) |
| Birth–Death | 1751 – July 7, 1977 |
| Age at Death | Reportedly 226 years (initially found to be 215 in 1966, later 226 in 1974) |
| Size | Approximately 70 cm (27.6 in) |
| Weight |
Approx not confirm 7.5 kg (16.5 lb) |
| Owner | Dr. Komei Koshihara (inherited from family) |
Its specialty was its longevity, which gave it a unique reputation worldwide and earned it the title of the longest-lived koi fish.
What makes something so Big?
His growth is not just a coincidence, but a series of important processes and special attention paid to him that enabled him to break the world record.
In which he was given temperature, seasonal growth, nutrition, healthy food, water quality, location, and genetics, in addition to the important things that are important for a koi fish.
Related topic: Why the Most Expensive Koi Fish Ever Sold?
1. Genetics
Only some types of koi fish grow to large sizes. Not all koi fish grow in size. Growing types such as Jumbo Koi, Chagoi, Kohaku, Showa, Ogon, and Benigoi successfully grow in size.
These are the types of koi that can grow to the maximum size.
Chagoi Koi are fast-growing fish that can grow to over 40 inches in length.
Kohaku Giant Koi have a strong genetic line for growing in length.
Showa and Sanke have a 30-inch limit, but both are capable of growing much larger.
Both Ogon and Benigoi have the chance to grow to more than 30 or 36 inches.
2. Water Quality and Location
The environment of a koi plays a very important role in its growth and development, and poor water quality can greatly affect the growth of koi fish, and a small pond for a koi hinders its growth.
If a large pond and good water quality for a koi allows it to grow its fish, then a large pond can be a way for a koi to increase its potential.
How large should the pond be? This pond should be 1000 plus. The larger the pond, the happier and healthier the koi fish.
Importance of Strong Filtration: A strong filtration is essential for koi because it prevents the accumulation of waste that koi collect and maintains water quality.
Water changes: Regular water changes to maintain the water level for the koi, which is fresh and maintains the ideal oxygen level.
3. Nutrition and Food
Koi’s diet directly affects its growth size; it is the food that hinders its growth. But if given the right direction and the right food? For example, high-protein, nutritious foods promote rapid growth and grow successfully themselves.
What and how much protein is needed to increase the size of a successful Koi without affecting its health? Suitable protein pellets for Koi are (35-40% protein food).
Koi also eats good food from vegetables such as fresh vegetables, peas, lettuce, etc.
Live foods such as worms or shrimp are also necessary for Koi, as they promote their growth
Avoid: Low-quality, filler-based koi food, which can prevent koi from thriving; otherwise, koi growth may be slowed.
4. Temperature
Some fish grow faster in warmer temperatures, but this can be a significant risk, as some fish have a slower metabolism and their growth and development slow down in the winter.
Normal temperature for growth: 70-80 ° F (21-27 ° C) is a must.
Stop feeding koi at temperatures below 50 ° F (10 ° C) because koi cannot digest food properly in cold water, which can have a negative impact on their health.
5. Seasonal Growth Cycle
| Season | Water Temp | Growth Activity |
|---|---|---|
| Summer | Warm (70–85°F) | Fastest growth |
| Fall | Cooling (70–50°F) | Growth slows |
| Spring | Rising (50–70°F) | Growth restarts |
| Winter | Cold (below 50°F) | Very little or no growth |
Can a backyard koi grow to a large size?
Yes, it is possible. If you have a 20 or 24-inch koi, it is possible that it can grow to 30 inches or even more with good and proper care, but this entire process depends on your care. However, your koi can grow to more than 40 inches, which usually requires a large pond.
Important tips for raising koi in your home
Provide at least 250 gallons of water or more responsibly for one koi.
Keep the water quality fresh and clean at all times for the health of the koi and use high-quality water filtration.
Feed the koi according to its needs and feed it high-protein foods, keeping in mind that overfeeding can affect the health of the koi.
Manage the water temperature according to the koi’s needs for year-round growth.
Final Thoughts
The Biggest Koi Fish in the World is a fish that thrives on its beauty and incredible abilities. With the right genetics, a good environment, and excellent care, it can live up to your expectations and live for decades.
It is important to understand that not all koi fish are big enough to set records, but with your good care, they will grow and stay healthy for years to come.
FAQs: Biggest Koi Fish in the World
1. What’s the Biggest Koi Fish Ever Recorded?
The biggest koi fish ever recorded was a massive koi named Big Girl, living in the UK. She measured over 4 feet (48 inches) in length and weighed around 90 pounds (40 kg). Big Girl was a giant Chagoi variety, known for fast growth and friendly behavior. Her record-breaking size made her famous in the koi-keeping world.
2. What is the $2 Million Koi Fish?
In 2018, a stunning Kohaku koi named S Legend was sold at an auction in Japan for approximately $1.8 million, often rounded up to $2 million. She was a female, high-quality Japanese-bred koi with a flawless white body and rich red markings. The buyer was from Taiwan, and the fish was expected to compete in high-level koi shows in Japan.
3. Can Koi Fish Live for 100 Years?
Yes, koi fish can live up to 100 years or more, although this is rare. The most famous example is Hanako, a scarlet koi from Japan that reportedly lived 226 years, from around 1751 to 1977. Most healthy koi in home ponds live 25 to 35 years, but with perfect care and genetics, some can live over a century.
4. What’s the Biggest a Koi Fish Can Get?
Under ideal conditions, koi can grow very large.
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Average domestic koi grow up to 12–15 inches (30–38 cm).
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Japanese koi often reach 24–36 inches (60–90 cm).
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Jumbo koi, especially Chagoi and Kohaku, can grow over 40 inches (100+ cm).
The biggest koi grow best in large, clean ponds with proper filtration and a high-protein diet.
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