Kali Tawa Rainbow

Kali Tawa Rainbow (Melanotaenia sp. ‘Kali Tawa’) is one of the most celebrated and sought-after rainbowfish in the hobby — described by rainbowfish legend Gary Lange as the 'most amazing rainbowfish' he had ever seen. Males display a dazzling combination of pastel blue body with brilliant white dorsal and anal fins, a vivid red tail, and — during display — an electric red-orange stripe that blazes across the forehead and transitions into turquoise blue along the back. Few freshwater fish can rival this display.

Feeding & Care Tip: Sera Vipan Tropical Flakes and Hikari Micro Pellets make excellent daily staples. Supplement 2–3× per week with Hikari Frozen or Freeze-Dried Bloodworms to develop the full display coloration. Crush flakes for juveniles; soak pellets. Juveniles are considerably paler than adults — full color develops gradually with maturity.

This species was first discovered in 2019 during a privately funded research trip and named for the Kali Tawa River in its place of origin in Papua New Guinea (some sources cite West Papua/Indonesia). It was introduced to the hobby in very small numbers from specimens collected by Gary Lange and remains exceptionally rare in the trade. A genuine collector's trophy.

Keep in groups of at least six with mixed sexes. Males display almost continuously throughout the day — one of the few rainbowfish that shows vivid color at all times, not just during peak display. The forehead flash — electric red-orange fading to turquoise — is particularly spectacular.

A well-planted aquarium with open swimming space in the center replicates the rainbowfish's natural riverine habitat. These are active, fast-swimming fish that appreciate length more than height — a longer tank allows them to build up speed and display properly. Good filtration and regular partial water changes are important, as rainbowfish are sensitive to deteriorating water quality. Avoid very small or slow-moving tankmates that may be outcompeted at feeding time.

Care & Ideal Parameters