Koi fish do indeed fight with each other, even though they are generally considered to be docile fish. Here is a specific analysis of koi fish fighting:
Reasons for Fighting
Insufficient Space: If the water body space for keeping koi fish is not enough, they may fight over territory.
Food Competition: When the food supply is insufficient, koi fish may fight for food.
Behavior during the Breeding Season: During the breeding season, koi fish may show stronger aggression, especially among males.
How to Reduce the Risk of Fighting
Provide Sufficient Space: Ensure that the fish tank or pond is large enough so that each koi fish has enough room to move around.
Guarantee Food Supply: Feed the fish regularly and in appropriate amounts to avoid fights caused by food shortages.
Avoid Keeping Aggressive Fish Together: There may be conflicts when koi fish are kept together with certain fish species (such as goldfish), so it is necessary to avoid keeping them with aggressive fish.
Special Situations
Size Difference: Larger koi fish and smaller koi fish can usually coexist peacefully because they don't bully their own kind.
Personality Difference: Some koi fish varieties may be more aggressive than others, so attention should be paid when choosing the varieties.
In conclusion, although koi fish have a gentle temperament, they may still fight under certain conditions. Through reasonable feeding and management, this risk can be effectively reduced.