Koi fish generally do not actively prey on other healthy fish under normal circumstances, but similar behaviors may occur under specific conditions. The specific reasons and precautions are as follows:
I. Possible Scenarios
1. Accidental Ingestion of Fry or Extremely Small Fish
If there is a significant size difference between mixed fish species (such as neon tetra fry), koi may mistakenly swallow them due to instinctive pecking.
2. Attacking Sick or Dying Fish
Koi will nibble on slow-moving or injured fish, which is a natural behavior to clean the water.
3. Hunger or Territory Disputes
Food scarcity over a long period may lead to attacks on other fish, and male koi are also more aggressive during the breeding season.
II. Mixed Farming Recommendations
1. Avoid Mixed Farming with Fragile Fish Species
For example, goldfish tails are easily nibbled by koi and should not be kept in the same tank.
Small fish (such as guppies) should also be avoided.
2. Ensure Sufficient Space and Food
Reduce territory disputes and feed special feeds (containing animal and plant proteins).
3. Pay Attention to Water Quality and Health Management
Deteriorating water quality will exacerbate conflicts. Regular water changes and isolation of sick fish are required.
III. Typical Feeding Habits of Koi
1. Main Diet
Algae, aquatic plants, insect larvae, and artificial feeds.
2. Special Behaviors
Koi may gently nibble other fish while playing or defending, usually without malice.
Conclusion
Under reasonable feeding, koi can coexist harmoniously with fish of matching sizes. If abnormal nibbling is found, the environment and fish status should be checked.