Port Moresby Rainbow
Port Moresby Rainbow (Melanotaenia parkinsoni) is a large, impressive rainbowfish with one of the most elegant color patterns in the genus. Males develop a warm orange to gold body with a series of bold horizontal orange and blue-grey stripes along the flanks, and vivid orange-red fins. The combination of warm tones and iridescent stripes gives this species a richness that is genuinely breathtaking in a large school.
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. Crush flakes for juveniles; soak pellets. High-protein supplemental feeding develops the full male coloration.
Native to the Kemp Welch River and surrounding drainages near Port Moresby in Central Province, Papua New Guinea. This species inhabits slow to moderate flowing, slightly alkaline waters with clear visibility. Its relatively large size means it needs a spacious aquarium.
Keep in groups of at least six with mixed sexes. Males are competitive in display but not aggressive. Near Threatened on the IUCN Red List — captive breeding populations are valuable. Completely peaceful with other large community fish.
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
| Difficulty | Easy |
| Temperament | Peaceful — Community |
| Typical Adult Size | 5.9 inches (15 cm) |
| Min. Group Size | 6 minimum — mixed sexes; needs a large aquarium |
| Ideal Temp | 75–86°F (24–30°C) |
| Ideal pH | 7.0–8.0 |
| Ideal GH | 8–20 dGH |
| Ideal KH | 4–12 dKH |
| Staple Food | Sera Vipan Tropical Flakes; Hikari Micro Pellets |
| Treat / Supplement | Hikari Frozen or Freeze-Dried Bloodworms |
| Origin | Kemp Welch River and surroundings, Central Province, Papua New Guinea |
| Notes | Near Threatened (IUCN). Large species — needs a tank of at least 4 feet. Warm orange-gold body with striped flanks is strikingly beautiful. Slightly alkaline water preferred. |
