Why Koi Fish Jump Out of the Water

Jumping behavior isn’t uncommon among koi species. Some pond keepers have noticed their fish jumping as high as two feet in the air or leaping from one end of the pond to the other. Chagoi carp, a friendly species that’s treasured in Japan because its scales match the color of tea leaves, is known to jump often out of playfulness. Shusui carp are as colorful as they are active, and this often results in jumping behavior. There are various other reasons koi jump out of the water. In some cases, the behavior may indicate issues with the aquatic ecosystem. The knowledgeable staff at Aquatic Warehouse, a trusted provider of koi pond supplies, would like to share a few of the reasons koi might jump.

Habitat Exploration Through Jumping

Elaborate gardening is an important aspect of Zen Buddhism, which is why some of the most beautiful koi ponds are in Japan. Religious grounds such as ceremonial parks and Zen monasteries in Japan are home to incredible ponds decorated with fountains, waterfalls, high rocky formations, stone paths, bridges, and viewing areas. When koi are raised in these habitats, which are often very large, they often want to explore them by means of jumping and swimming. When new juveniles or adults are introduced to a large pond, they’re more likely to jump.

Mating and Breeding

Male koi compete against each other for the attention of a female who’s ready to breed. This mating behavior can be aggressive but generally not dangerous, and it may result in jumping. Most female koi won’t release their eggs unless they’re actively pursued by males, and this is another situation in which jumping can happen. In this case, the jumps won’t be very high. They’ll mostly just break the water’s surface.

Reaction to Hand-Feeding

Large and friendly koi such as the aforementioned Chagoi are perfect for hand-feeding, and they can get used to this very quickly. There will come a time when Chagoi koi associate the proximity of humans with feeding, and this is when some jumping may occur. Always keep a count of your species and look around the edges of the pond in case a fish has jumped outside.

Water Quality and Low Oxygen Levels

When you see several koi leaping out of the water repeatedly, this may be a sign that not all is well with regard to water chemistry. If your pond is equipped with an aeration system that’s suddenly turned off or too much water is added without proper dechlorination, you may see frantic jumping before the end of the day, and this should be interpreted as lower oxygen levels or as a toxic condition. In ponds where sturgeon fish are kept, seeing them jump out means very low oxygenation. When you see what appears to be desperate jumping out of the water, this is a good time to check the water chemistry with strips that provide information about pH, nitrites, nitrates, alkalinity, and water hardness. Finally, to determine if an emergency water change is needed, you should also dip an ammonia test strip or use the much more accurate titration test kits:

https://www.aquaticwarehouse.com/testing-/api-freshwater-master-test-kit

To maintain a healthy pond environment for your koi, it’s vital to obtain several necessary supplies. From pond vacuums and filters to nutritious koi food and supplements, you can find everything you need at Aquatic Warehouse, located in Kearny Mesa. You can order the supplies you need on our website, and you can also give us a call at 858-467-9297 if you have any questions.