Parkinson's Rainbowfish

Adults can reach up to 11 cm in length. These fish are characterized by pronounced sexual dimorphism, manifested in differences in coloration. Males are generally more colorful due to the presence of a red-orange pigment that unevenly covers the caudal half of their body. Sometimes, individuals with a predominance of yellowish hues in their coloration are found. Unlike males, females have a more uniform coloration, most often in gray or silver tones. Young fish look similar to females; their bright colors only appear as they mature. In both sexes, rows of stripes may be visible along the lateral line.

The species is endemic to Papua New Guinea. In nature, it inhabits river systems located between the Kemp Welch River and Milne Bay. The fish prefer to inhabit lowland areas of tropical rainforests, choosing bodies of water with clear, well-aerated water and moderate current. Typical biotopes are characterized by dense aquatic vegetation and an abundance of shelters.

This peaceful and active fish needs the company of its own kind. It is recommended to keep a school of 6–8 individuals. Although males compete with each other for the attention of females, serious injuries are extremely rare. They get along well with many other non-aggressive fish species. However, it should be noted that slow or timid aquarium inhabitants may experience stress due to their high activity.

For comfortable keeping of a group of 6–8 fish, the optimal aquarium volume starts from 140–150 liters. Since Parkinson's Rainbowfish are very active swimmers, the width of the aquarium is more important for them than its height. When decorating, sufficient large open areas for swimming should be left, and excessive overgrowth with aquatic plants should be avoided. Given their tendency to jump out, an aquarium lid would be very useful. These fish adapt well to various conditions, but an environment with high hardness (GH) and pH values is considered most comfortable for them. They prefer high water temperatures, while it is important to ensure a sufficient level of dissolved oxygen. Being omnivores, they readily accept popular dry, live, and frozen foods, such as mosquito larvae and daphnia. Interestingly, these fish can also feed on duckweed.

This omnivorous species readily accepts a variety of foods: both dry and live or frozen, such as mosquito larvae or daphnia. It has been observed that these fish are not averse to feasting on duckweed. Breeding does not present particular difficulties; the fish can spawn throughout the year in a healthy aquarium. However, the breeding process is complicated by the fact that spawning can last from one day to several weeks. Since Parkinson's Rainbowfish do not exhibit parental care, it is recommended to transfer the eggs to a separate tank to prevent them from being eaten by adult fish. The incubation period is determined by water temperature; at 28°C, it lasts about 8–10 days. After hatching, the fry remain motionless for several hours, and then begin to actively swim in search of food. Their first food can be infusoria or special suspensions for feeding fry. As they grow, they transition to powdered foods, Artemia nauplii, and other suitable types of nutrition.

These fish do not require special conditions for breeding. In a thriving aquarium, spawning can occur throughout the year. However, the breeding process is complicated by the fact that the spawning period can last from one day to several weeks. Parkinson's Rainbowfish do not exhibit parental care, so to protect the eggs from being eaten by adult fish, they must be timely transferred to a separate tank. The duration of the incubation period depends on the temperature: at 28°C, it is 8–10 days. After hatching, the fry remain in place for several hours, and then actively begin to swim in search of food. Infusoria or specialized suspensions for fry are suitable as their first food. As they grow, they begin to accept powdered foods, Artemia nauplii, and other appropriately sized foods.

The species has a strong immune system when kept in a stable environment. The main dangers are bacterial infections and parasitic infestations arising from stress due to sudden fluctuations in water parameters or poor filtration. For prevention, it is necessary to maintain aquarium cleanliness, avoid overpopulation, and ensure good aeration.

When choosing individuals, pay attention to the following signs:

• activity and absence of signs of lethargy or apathy
• clean skin, absence of spots, ulcers, or film
• intact fins and absence of damage
• normal breathing without signs of rapid gill movement

It is recommended to purchase a group of fish, as they experience severe stress when alone, which negatively affects their coloration and behavior.