Kali Tawa Rainbowfish 1.5-2”

Kali Tawa Rainbowfish, Melanotaenia sp. “Kali Tawa”, is an undescribed rainbowfish known from aquarium trade collections attributed to the Kali Tawa drainage in the Papuan region of Indonesia. This locality lies on the island of New Guinea and is part of the diverse freshwater river systems of western Papua. Because this fish has not been formally described in the scientific literature, its confirmed natural range is limited to this collection locality, and it is treated in the hobby as a distinct but undescribed Melanotaenia.

Adult Kali Tawa Rainbowfish typically reaches around 2.5 to 3 inches in length. Despite its relatively small size, it has a deep, laterally compressed body that gives it a strong visual presence in the aquarium. Coloration is one of the species’ main attractions, featuring a bright metallic base with vivid yellow, orange, and blue-green highlights that intensify as the fish matures and settles in. The fins are boldly colored, and males develop deeper bodies, higher dorsal profiles, and significantly stronger coloration than females, especially when competing or displaying within a group.

A tank of at least 30 gallons is recommended for a proper group, with larger tanks always beneficial. Kali Tawa Rainbowfish are active, fast-moving schooling fish and should be kept in groups of six or more to display natural behavior and full coloration. The aquarium should provide ample open swimming space with plants, wood, or other structure concentrated along the edges to create visual breaks without restricting movement. Moderate water movement and good circulation are preferred, as this species thrives in clean, well-oxygenated water.

Water conditions are relatively flexible compared to many rainbowfish. Kali Tawa Rainbowfish adapt well to neutral to moderately alkaline water and do not require extreme parameters. Temperatures between 74 and 80°F are appropriate. Stability and water quality are far more important than exact numbers, and regular water changes help maintain health, coloration, and activity.

Feeding Kali Tawa Rainbowfish is easy and consistent. In the aquarium they readily accept high-quality flakes, micro-pellets, and frozen foods such as brine shrimp and bloodworms. They are enthusiastic feeders and benefit from a varied diet that supports coloration, fin development, and overall condition.

Temperament is peaceful, energetic, and social. Kali Tawa Rainbowfish do well in active community aquariums with other similarly sized, non-aggressive fish. Suitable tankmates include other small rainbowfish, barbs, appropriately sized tetras, and peaceful bottom dwellers. Aggression is minimal, though very timid species may be overwhelmed by their constant motion.

Breeding is possible in captivity. Like other rainbowfish, Kali Tawa Rainbowfish are egg scatterers that deposit adhesive eggs among fine-leaved plants or spawning mops. Adults do not provide parental care, and eggs or fry should be removed if intentional breeding is desired.

Melanotaenia sp. “Kali Tawa” is a compact but vividly colored rainbowfish that offers strong visual impact without the space requirements of larger species. When kept in proper groups with clean water and adequate swimming room, it becomes a lively, constantly moving highlight that showcases the appeal of New Guinea rainbowfish in a manageable size.