The Size Range of Koi
Koi have a relatively large size range. Generally, they can reach a length of 0.6 to 1.5 meters and weigh between 10 and 45 kilograms. Under favorable rearing conditions, the length of koi can even reach 1.5 meters, and their weight can exceed 45 kilograms.
The Relationship between the Growth Rate and Age of Koi
The growth rate of koi varies at different ages. From birth to the first six months, koi can grow by 0.71 millimeters per day and approximately 2.13 centimeters per month. Between 6 and 12 months, they grow by about 0.58 millimeters per day and approximately 1.74 centimeters per month. At one year old, their body length is about 23.3 centimeters, and at two years old, it is about 39.6 centimeters. Koi grow rapidly before the age of 6.5 and can reach 50 to 70 centimeters. As they get older, their growth rate will gradually decline.
The Impact of the Rearing Environment on the Growth of Koi
The rearing environment has a significant impact on the growth of koi. If they are raised in a small fish tank, due to the limited space for movement, koi can only grow to two or three inches. However, if they are raised in a large fish tank or an outdoor pond, koi can quickly grow to 30 centimeters or even larger. In addition, an environment with longer periods of sunlight also helps the growth of koi. For example, in southern China, koi grow faster.