Butteryfly Koi 6"-8"
Butterfly koi are not technically koi according to strict Japanese definitions of the word, but rather a cross between long-finned Indonesian carp and traditional koi (which are also in the carp family). For the casual koi keeper, though, they are koi in all the ways that count: size, longevity, behavior, coloring, diet and general appearance.
Where butterfly koi differ from regular koi are their fins. Unlike traditional koi, which have genes that tell their fins to stop growing at a certain point, butterfly koi fins keep getting longer throughout their lifetimes. The result is the long, flowing fins that some pond owners love. Butterfly koi's bodies also tend to be slightly more slender than traditional koi's, and their barbels - the whisker-type growths on their faces - grow slightly longer.
UPKEEP OF YOUR KOI
Are you an experienced koi owner? Then you already know how to care for butterfly koi; their upkeep is almost identical. Feed your butterfly koi just as you would a regular koi, keep your water aerated and make sure they have plenty of shelter from the sun and predators. Butterfly koi are just as docile as other varieties, so feel free to place them in ponds with goldfish, catfish, orfes or other koi.