Wanam Lake Rainbowfish

Adult males can reach a length of about 9 cm. Their coloration has a greenish tint with a noticeable metallic sheen, and their belly shimmers with yellow-orange tones. Below the lateral line, thin orange stripes can be distinguished. The anal fin is significantly enlarged, growing up to 3 cm. Females are typically slightly smaller than males, measuring around 8 cm. Their coloration is less vibrant and more uniform, with a predominance of pale greenish tones.

The species is endemic to Lake Wanam in Papua New Guinea. Located in a valley surrounded by hills, the lake has a maximum depth not exceeding 20 meters. The shallow shoreline is rich in aquatic vegetation, including water lilies, among which schools of Bluish Glossolepis and Fasciata Rainbowfish find refuge. Today, this species is on the verge of extinction in the wild. The main reason for this is invasive species that have appeared in the lake: Tilapia cichlids, carp, and Gambusia. The first two species were introduced for commercial fishing, providing food for local residents, while Gambusia was intended to combat mosquito larvae.

This active fish is peaceful and feels most comfortable in a group of its own kind. Therefore, it is recommended to acquire a school of 6–8 individuals. It interacts well with other species that are comparable in size and temperament. For example, Tetras, Barbs, Danios, as well as some types of small catfish such as Corydoras, and other Rainbowfish, will make excellent tank mates.

The optimal aquarium volume for keeping a school of 6–8 fish starts from 80 liters. In terms of decor, it is preferable to combine areas with open water for free swimming and zones with dense aquatic vegetation. Water parameters should be alkaline on the pH scale, with medium to high hardness levels. It is important to note that the Wanam Lake Rainbowfish is not suitable for aquariums with soft water. When choosing a filter, preference should be given to a model that does not create excessive current. Aquarium maintenance is standard and includes regular procedures: weekly partial water changes with fresh water, removal of organic waste, and keeping equipment in good working order. As for diet, these fish are undemanding and readily accept most common foods, whether dry, freeze-dried, frozen, or live.

The fish is undemanding in terms of diet and readily accepts many known types of food available on the market: dry, freeze-dried, frozen, as well as live foods.

The Wanam Lake Rainbowfish is an egg-laying species. To stimulate spawning, it is recommended to use a breeding tank with fine-leaved plants or synthetic substrates, where the female lays her eggs. The breeding process often occurs at a water temperature of 26–27°C. After spawning is complete, the parents should be removed to prevent them from eating the eggs. The incubation period is 7–10 days, after which fry emerge, which are fed infusoria or rotifers, followed by a transition to Artemia nauplii.

The species has moderate resistance to diseases when water parameters are maintained, but it is sensitive to sharp changes in the chemical composition and quality of the environment. Typical problems with poor care can include bacterial infections affecting the skin and fins. Prevention includes maintaining stable pH and hardness levels, regular water changes, and providing a complete diet. It is important to avoid overpopulation, as stress reduces the fish's immunity.

When selecting individuals, attention should be paid to the activity of the fish and the cleanliness of their skin. A healthy rainbowfish should have a robust physique without visible damage, ulcers, or signs of emaciation. Avoid purchasing fish with signs of hybridization if the body shape or coloration appears atypical for the species. It is recommended to inquire about the origin of the individuals from the seller, preferring specimens from aquarium breeding, as wild populations are endangered.