Lake Sentani Rainbowfish

Males of this species can grow up to 12 centimeters in length, while females are typically smaller, reaching approximately 10 centimeters. The fish's body is laterally compressed, and its head is pointed. The main body color is silvery-blue; the back often shimmers with silver or takes on greenish hues. Orange and red tones can be observed on the belly. Narrow stripes run along the lateral line, alternating between blue (or green) and orange (or red) colors.

The species is endemic to Lake Sentani and its tributaries on the island of New Guinea (West Papua, Indonesia). These fish prefer to inhabit the pelagic layers of tropical freshwater bodies. In their natural habitat, water parameters are characterized by a temperature range of 24–28°C.

This fish is distinguished by its peaceful disposition and active behavior. It feels comfortable in a group of its own kind, as well as in the company of other fish of similar size and character. Compatibility with other species of similar temperament is usually good.

For a school of 6–8 individuals, an aquarium of 150 liters or more will be optimal. When decorating, it is recommended to create open swimming spaces, as well as providing areas with shelters formed by dense plant thickets and natural snags. The water composition in Lake Sentani is not stable due to numerous tributaries, and its parameters vary depending on the season. Thanks to these conditions, the fish have adapted to a wide range of pH and GH values, which greatly simplifies water preparation for aquarium care. Aquarium maintenance is standard and includes regular procedures: weekly partial water changes and timely removal of organic waste. This species is omnivorous and readily accepts most common dry foods, as well as fresh or frozen products, such as small zooplankton.

This species is omnivorous. These fish readily consume most available dry foods, as well as various fresh or frozen food products, including small zooplankton.

Spawning is paired or group-based and requires a separate species-specific aquarium to prevent hybridization with other members of the genus. Eggs are laid on fine-leaved plants or substrate. The incubation period at a temperature of about 26°C is approximately 12 days. Fry after hatching are extremely small and require very fine starter food, such as infusoria or copepod nauplii, gradually transitioning to larger foods.

Lake Sentani rainbowfish are susceptible to diseases typical of the Melanotaeniidae family, which arise when keeping conditions are violated. The fish are sensitive to water quality, so the accumulation of organic waste and high levels of ammonia or nitrites quickly provoke bacterial infections, manifesting as fin erosion, ulcers, or cloudy mucous membranes. Also, under stress caused by sharp fluctuations in parameters or overcrowding, the species is prone to ichthyophthiriasis (white spots on the body) and fungal infections. Disease prevention involves maintaining stable water parameters and regular water changes. A particular danger is the species' tendency to hybridize with other members of the genus, which, in uncontrolled breeding, weakens the immunity of the offspring and leads to population degeneration. To maintain fish health, it is recommended to avoid keeping them in the same aquarium with closely related species, as this not only leads to a loss of line purity but also complicates the diagnosis of species-specific conditions due to the external similarity of individuals.

When selecting individuals, attention should be paid to the purity of the line, as the species is extremely rare and has often been crossbred with closely related species. Healthy fish should be active, have clean fins without signs of erosion, and a robust physique. Avoid purchasing individuals from aquariums where other species of the genus Chilatherina are kept, to eliminate the risk of buying hybrids. It is critically important to ensure the absence of external parasites and signs of emaciation in the fish in the retail aquarium.