The Dwarf Neon Rainbowfish Melanotaenia praecox was described by Weber and Beaufort in 1922, but was first introduced in 1992. They are found in the small, lush jungle streams in Western New Guinea (formerly Irian Jaya), the Mamberamo region of West Papua.
The Dwarf Rainbowfish inhabit swift moving clear waters. These Rainbows usually live in water that stays around 75 - 82 degrees with a pH of around 6.5. These fish feed on vegetation, insects, small worms and fish eggs. Their region has not been well surveyed so the extent of their reach in that area can not be certain. There is currently insufficient data as to their status, but the Dwarf Rainbowfish were last listed in 1994 as a rare species