The colorful koi fish have their ancestor belonging to the ancient dynasty of China, in the 4th century. The Koi fish or Nishikigoi are usually kept in koi ponds located outside the home for decorative purposes.
Their white body with bright orange spots is what sets them apart from most other fish in the pond.
The modern Japanese Koi, however, are believed to hail from 19th-century Japan, where they were bred cautiously by rice farmers. They originally belong to the Cyprinidae family of fish and typically live for 25 – 35 years.
With proper care, good genetics, and feeding habits, some koi fish may even outlive their owners and stay alive for 100 years.
Read on to know more about the lifespan of koi fish!
Which Is the Oldest Koi Fish to Ever Live?
Imagine outliving not only your parents but also your great-great grand fish! For Hanako, the scarlet koi fish, this was a reality. Hanako, aged 226 years, was with Dr. Komei Koshihara during her last swims.
In 1974, the study of the growth rings of one of Hanako’s scales proved that she was 223 years old at the time. She thrived for 3 more years, before peacefully passing away in Japan, in 1977, aging 226 years old. She, therefore, might have been the oldest living Koi fish in the world.
Also check: How Much Are Koi Fish?
How Long Can Koi Fish Live Without Food?
Although fish should never be kept without food under general conditions, Koi fish can survive for fourteen days or two weeks. The koi fish have an otherworldly ability to use their metabolism to survive for a long time without food.
This is during the peak season of summer when it has been fed regularly.
However, this should not be taken as an excuse to not feed them regularly. The koi fish should be fed once a day. Note that the quantity of the food depends on the season and the temperature of the water they are currently in.
It is very important to feed your Koi fish properly in the summer season, otherwise, they will enter the winter season in poor health conditions. By the time spring arrives, sickness might cause them to pass away.
How Long Do Koi Fish Live In Captivity?
In captivity, koi fish live up to 25 – 35 years approximately. However, in the wild, they live only for 15 – 20 years as they have to fend for themselves. It is not rare to see a 70 or 100-year-old koi fish in Japan. If kept well in captivity, they can live longer.
Koi fish are easy to keep in an aquarium and they can adapt to a new environment quickly and grow according to the space. They are quite strong and thrive better when kept in groups.
However, the number of koi fish in a pond should be checked as they become aggressive with age. They normally live decades longer when reared alone.
The ideal temperature for koi fish to survive in is 59 to 77 degrees Fahrenheit and they thrive in cold water. A pond that accommodates koi fish should have shallow and rear ends for the fish to comfortably live in the shallows and not freeze to death.
The pH level in a koi fish pond should be around 7.2 – 7.4. A low pH level of pH 5 might trigger a condition called Acidosis and kill koi fish within a few days.
How Long Do Koi Fish Grow?
Koi fish normally grow up to 12 to 15 inches long when fed a proper diet and taken care of properly. However, the size varies as Japanese koi fish can grow up to a size of 22 to 26 inches and a rare type of jumbo koi fish can grow up to 34 to 36 inches in length.
They grow up very slowly, and a koi fish brought up under standard conditions will reach a length of 6 to 8 inches in the first year. It reaches its full size in about 3 years.
How Long Do Pond Koi Fish Live For?
Domesticated koi fish that live in a fairly maintained pond live for about 15 to 20 years. However, Japanese koi fish can live longer, up to 200 years when kept in a perfectly well-maintained pond, with the perfect temperature, reared on a proper diet, and has good genetics.
How Long Do Koi Fish Live in a Small Pond?
Even though koi fish like to live in groups during the initial stages of their life, with old age they become aggressive. Therefore, it is advised that koi fish are kept individually as they grow up. They are cold-water fish and demand a large environment.
An ideal pond for koi fish to survive well in is 1000 gallons and a minimum of three feet in height. Small ponds can soon kill your koi fish as it limits the space for the creature and increases discomfort for your fish. They will live up to 15 years in a small and uncomfortable pond.
Factors Affecting the Longevity of Koi Fish
1. Genetics
Genetics plays a huge role in the life span of koi fish. Under natural conditions koi fish normally live up to 25 – 35 years. However, Japanese koi fish have a greater life span of 40 – 70 years and some might even live for 200 years when properly taken care of.
Japan has been rearing koi fish for a very long time and therefore, the koi fish found there have developed genes that make each generation of koi fish better than the previous.
2. Food
One of the most important factors related to the life of a koi fish is what they are fed.
Western koi fish farmers usually obsess over the size of the fish and rear them on a rich diet. Even though this helps them reach a bigger size, it is very bad for their health and cuts short their life by a few years.
Japanese fish breeders keep their koi fish in natural earth dams to allow them to gain strength and weigh more naturally. This is a far better way to raise your koi fish, as richer diets can make your fish obese and eventually end their life sooner than expected.
3. Winter Temperature
The life of your koi fish also depends on the temperature of the tank or pond in which they are kept. Koi fish hibernate during the winter season, which stretches out their life span.
Winters in Japan are cold, which is why koi fish there can hibernate for a longer time. Thus, living for a longer time.
4. Care
The lifespan of a koi fish also depends on the type of koi fish it is. Modern koi fishes, such as Utsurimono are different from the ancient species of koi such as Kohaku. However, the lifespan of a koi majorly depends on how the owner takes care of the fish.
If the koi are kept in a fairly large pond, with a water filter and lots of room for them to travel in, the fish can thrive happily. The diet of koi fish should also be taken care of by the owner and the fish should be fed daily.
After the food is given, the koi fish naturally spends 5 minutes devouring the food. If there is still food left after 5 minutes, less amount of food should be given to them the next time.
A proper environment should also be maintained for the koi to thrive. Koi fish enjoy staying in groups when young. But, with age, they should be allowed to stay individually with sufficient room to grow as age turns them aggressive.
Frequently Asked Questions
Do Koi Fish Live Longer Than Goldfish?
Both Koi Fish and goldfish reach their complete length in about 2 – 3 years. However, the average life span for a koi fish is 25 – 35 years and that of a goldfish is just 10 years.
Are Koi Fish Intelligent?
Koi fish are a pretty intelligent species. They are known for their great memory, patience, loyalty towards their owners, and personalities bigger than the tanks they reside in.
Do Koi Fish Get Lonely?
Koi fish are extrovert fish that feel the safest when kept in groups. A few koi fish should be reared together to avoid them from getting lonely in the due course of time.
Do Koi Fish Need Sunlight?
Koi fish under normal circumstances can tolerate sunlight for about 5 – 6 hours. However, they also need to be in the shade after that.
A proper balance should be maintained to keep them thriving. Natural protection from the sunlight, such as lily pads, water trees, and rocks, should be used in abundance when building their ponds.
How to Tell if Your Koi Fish Are Happy?
Koi fish are simple creatures and swim around the pond lazily when in a happy mood. When feeding them, they tend to gather around the owner and at times push their tiny heads through the surface of the water when excited. Koi fish are more energetic during warmer temperatures.