Parkinson's Rainbowfish

Adults reach up to 11 cm in length. The species shows pronounced sexual dimorphism in colouration. Males are more colourful, displaying red-orange pigmentation that covers the rear half of their body unevenly. Some individuals have yellowish tones in their colouration. Females have more uniform colouring, typically grey or silver. Young fish resemble females; bright colours develop as they mature. Both sexes may show rows of stripes along the lateral line.

This species is endemic to Papua New Guinea. In the wild it inhabits river systems between the Kemp-Welch River and Milne Bay. The fish favour lowland areas of tropical rainforests, choosing clear, well-aerated waters with moderate flow. Typical habitats feature dense aquatic plants and plenty of hiding places.

This is a peaceful, active fish that needs to live with others of its kind. A group of 6–8 individuals is recommended. Males compete for female attention, but serious injuries are rare. They get along well with many other peaceful species. However, slow-moving or shy tank mates may become stressed by their high activity levels.

A group of 6–8 fish requires a minimum aquarium volume of 140–150 litres. Since Parkinson's rainbowfish are very active swimmers, tank width is more important than height. Provide large open areas for swimming and avoid excessive planting. A lid is advisable, as this fish can jump. They adapt to various conditions but prefer high hardness and pH. They need warm water and sufficient dissolved oxygen. As omnivores, they readily accept popular dry, live and frozen foods such as mosquito larvae and daphnia. They will also eat duckweed.

This omnivorous species readily accepts a variety of foods: dry, live and frozen, such as mosquito larvae and daphnia. The fish will also eat duckweed.

This species has no special breeding requirements. Spawning can occur year-round in a well-maintained tank. However, the spawning period can last from one day to several weeks, which complicates breeding. Parkinson's rainbowfish do not care for their eggs, so they must be moved to a separate tank to prevent the adults from eating them. Incubation time depends on temperature: at 28°C it takes 8–10 days. After hatching, fry remain in place for a few hours, then actively search for food. Infusoria or specialized fry suspensions work as a first food. As they grow, they accept powdered food, brine shrimp nauplii and other appropriately sized foods.

The species has a strong immune system when kept in stable conditions. The main risks are bacterial infections and parasitic diseases caused by stress from sudden changes in water parameters or poor filtration. Prevention requires maintaining a clean tank, avoiding overstocking and ensuring good aeration.

When selecting fish, look for the following: — activity and no signs of lethargy or apathy — clean skin with no spots, wounds or coating — intact fins with no damage — normal breathing without rapid gill cover movement It is recommended to buy a group, as solitary fish experience severe stress, which negatively affects their colour and behaviour.