Koi will not recognize its owner. The brain of koi fish is not developed enough and does not have the ability to recognize its owner. If the owner appears next to the fish tank and the koi fish swims with the owner, this is not because they recognize the owner, but a conditioned reflex. When the owner feeds the koi fish regularly every day, the koi fish will form a conditioned reflex over time.

Notes on raising koi:

1. When choosing koi, you must choose fish that are healthy, uninjured, and free of scales. The body is bright, with various colors and clear boundaries.

2. Koi does not have high requirements for water quality and is suitable for living in a slightly alkaline and low hardness water environment. The suitable water temperature is around 2-30 degrees, but koi cannot resist sudden changes in water temperature. Koi fish will feel uncomfortable if the temperature difference changes suddenly by 2-3 degrees.

3. Koi is an omnivorous fish and can be fed with algae or synthetic granular bait. It can also be fed with fragments of molluscs and higher aquatic plants.