Koi are a friendly fish. Upon arrival in your pond, they may take time adjusting and familiarizing themselves. After quarantining your koi, set a feeding schedule and stick to it. Once these koi have become accustomed to their new environment and to you, they will get friendlier. When feeding them, make sure to sit by the pond so that they learn to recognize you. Koi that grow comfortable enough with their keepers will come to the surface and eat out of their hands. They may even leap out of the water as you walk by!
Koi act differently when they’re stressed, which comes from new or unfamiliar situations. They also hate quick changes – especially when being moved into a new pond or tank, or rapid temperature fluctuations. A stressed out koi may skip out on a feeding by hanging near the floor of the pond. They may become less friendly and more lethargic. Sometimes stressed koi will jump or rub against the edges of a pond. Stress also manifests itself in koi fins. They may look bloodshot or ragged at the edges.
There are many factors that result in a stressed koi. They may be threatened by predators outside of the pond. The water may have been polluted by fertilizer run-off. Or, the problem could be inside the pond. Run a water test to make sure all chemical needs are being met. If the pond is overpopulated, this may also be stressing your koi out too.