It’s not just relaxing to see koi swimming gracefully―it’s also a good sign. When they move well, feed regularly, and exhibit no signs of external parasites, you have a happy koi.

What signs should you watch out for that will tell you when a koi is not well? Edward enumerates the following:

1. Parking: This is the term that refers to when a koi prefers to stay at the bottom of a pond and rarely moves. Possible causes are stress to the koi during transport and bacterial or parasitic infections. The parking behavior can lead to wounds or ulceration.

2. Reddening of the veins and/or skin, with the pectoral fins clasped or folded: This can be due to stress, which in turn can lead to bacterial infections.

3. Flashing: This refers to when a koi scratches at the bottom or sides of the pond and sometimes jumps to the surface. This can be due to a parasite infestation or poor water conditions.

4. Gasping: When your koi gasps for air at the surface of the water, this can be a sign of parasite infection or that the water in the pond is not fully aerated.

5. Nervousness: If koi are scared, they can sometimes dart around quickly and hit the walls of their pond, which can cause bruising and sometimes death.

This story appeared in Animal Scene’s April 2015 issue.