Butterfly koi originated in the mid-20th century as a result of an effort to increase the hardiness of traditional koi. Japanese breeders interbred wild Indonesian longfin river carp with traditional koi. The resulting fish had longer fins, long barbells, pompom nostrils, and were hardier than koi. These were known in Japan as "onagaoi" or "hire naga goi", or translated in English "long tail carp". Randy LeFever, the son of Wyatt LeFever, a noted breeder of koi, is credited with suggesting they looked like butterflies, a trait for which the breed is named. They are also sometimes referred to as Dragon Koi. For clarification, the word koi is wholly inaccurate for describing these fish; Koi are, as dictated by the Japanese breeders, Nishikigoi, these long-finned carp are Hirenagagoi. The word koi has been given to these fish to increase their resale value and popularity in garden centres and the like.