The Size Range of Koi
Koi have a relatively wide size range. Generally, they can grow to be 0.6 to 1.5 meters long, with a weight ranging from 10 to 45 kilograms. Under favorable feeding 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, which is approximately 2.13 centimeters per month. Between 6 and 12 months, they grow by about 0.58 millimeters per day, 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 a length of 50 to 70 centimeters. As they get older, their growth rate will gradually decline.
The Influence of the Rearing Environment on the Growth of Koi
The rearing environment has a significant impact on the growth of koi. If they are reared in a small fish tank, due to the limited space for movement, koi can only grow to be two or three inches long. However, if they are reared in a large fish tank or an outdoor pond, koi can quickly grow to be 30 centimeters or even larger. In addition, an environment with longer exposure to light also helps the growth of koi. For example, in southern China, koi grow faster.