Butterfly koi fish are a beautiful and graceful variety of koi that have grown in popularity in recent years. Contrary to popular belief, the hybrid fish is not a cross between the closely related koi and goldfish. The butterfly koi’s origin is unknown but rumored to be Indonesia. Many believe it is a descendent of koi and Asian carp. In koi breeding, a very traditional sport, butterfly koi have yet to be highly recognized at shows. For some koi connoisseurs, butterfly koi are not considered in the same league as traditional koi. Others love butterfly koi for their long, flowing fins that look similar to a butterfly’s wings.
While koi fish have had a long history of breeding in Japan, butterfly koi have had a much shorter and more recent history. As koi keeping and breeding grew in popularity in the last century, new varieties of koi began appearing in the 1980s. Butterfly koi emerged at this time from New York, where breeders had purchased dull-looking long-finned carp from Indonesia.
Butterfly koi have fins that are much larger in proportion to their bodies than other varieties of koi. Butterfly koi’s fins are maximized to their full potential when they are allowed to grow steadily and slowly. While normal koi’s body to fin to body ratios are usually 1:5, a butterfly koi’s is more like 1:3 and in rare occasions their fins can grow as long as their bodies. These fins will just grow longer and more beautiful as a koi matures.
These fins, while a marker of beauty, are also easily damaged. Long and delicate, butterfly koi fins can be damaged by netting and even from simply handling the koi. These fish must be handled with extra care.
Butterfly koi are gaining popularity in the United States. They are a calm and peaceful fish and some smaller sizes can be kept in aquariums. However, like traditional koi, it is recommended that they are grown in a pond to reach their full size potential. Butterfly koi are a hardy fish that hold up well over time and can be found at most pet retailers.