When first introduced into the aquarium hobby in the 1970’s, only males of the species were available. Today, however, both sexes of Threadfin Rainbowfish can be found. These fish exhibit dark coloration along their backs and males of the species may have a reddish tint on the dorsal fin and caudal lobes. Males of the species also develop thread-like extensions to the fins for which the fish is named. This species is also sometimes sold under the name Featherfin Rainbowfish. Threadfin Rainbowfish are native to Papua New Guinea, Indonesia and Australia where they can be found in slow-moving waters. These fish tend to inhabit streams, swamps and lagoons as well as drainage ditches. The favored habitats of these fish are densely vegetated.