Melanotaenia sp. 'Panda' is one of the most unusually patterned undescribed rainbowfish in the hobby, collecting from the Fly River system of Papua New Guinea. The common name derives from a strikingly unusual pattern — the anterior half of the body, including the head and forebody, is conspicuously pale silver-white, while the posterior body, caudal peduncle, and tail are considerably darker blue-grey to slate, creating a bicoloured effect reminiscent of a giant panda's contrasting markings.
This is a genuinely rare species in captivity, known from very few import events, and hobbyists maintaining it are contributing to the documentation and conservation of undescribed New Guinean biodiversity. Care requirements are similar to other Fly River Melanotaenia — moderately hard, slightly alkaline water, good oxygenation, and a spacious planted aquarium.
The 'Panda' pattern is most strongly expressed in dominant males and appears to function as part of the species' courtship display repertoire. Hobbyists who have kept this species report that it is not particularly delicate in care but breeds less freely than more domesticated Melanotaenia, often requiring dedicated spawning setups and careful conditioning.