How do koi fish behave?

Koi are a friendly fish. Upon arrival in your pond, they may take time adjusting and familiarizing themselves. 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.

Are koi aggressive?

Although koi are usually gentle fish, they can become aggressive due to poor conditions, diet or unsuitable pond mates. Though koi are typically gentle and easygoing fish, they can at times be aggressive and may bully other fish depending on the circumstances.

Why do koi come up for air?

Do You Have Too Many Plants? Plants may release subsurface oxygen to the water during the day, but at night those plants take in oxygen, which means your fish may be gasping for air.

Do koi bite humans?

It is a question as old as koi are, which is over one hundred years, and the answer is simple – yes koi do bite. A koi fish bite will only tickle you, but their little nibbles help them eat food from the bottom of your pond and can be dangerous to other fish.

Can koi hear?

Even though they do not have external ears, they can hear. Koi sense vibrations in the water and hear with the Wesberian Ossicles, a group of bones that are connected on one end to the forward swim bladder and on the other end to the auditory center, a sensing organ that resembles our inner ear.

Why does my koi jump out of the water?

A lack of oxygen is a common reason that Koi fish jump out of their pond. Increasing the oxygen level is often a simple process, though you may have to try multiple solutions to raise it sufficiently. Dissolved oxygen is lower the warmer that the water gets.

Why is my koi flashing?

‘Flashing’ is usually (but not always) a sign of an irritated fish. It may be due to parasites, high ammonia or Nitrite or any other source of irritation to the fish. The fish are already stressed and adding more stress through a water change will do more harm than good.