Rainbow Flagfish

Rainbow Flagfish (Aplocheilus lineatus)

The Rainbow Flagfish, also known as Golden Wonder Killifish, is an attractive killifish species known for its vibrant coloration and active swimming habits. They display a blend of red, green, and blue hues, making them a visually appealing addition to an aquarium. Males are typically more colorful, with a red stripe along their body.

These fish grow to around 2.4 inches in length and have a somewhat territorial personality. Rainbow Flagfish do best when kept in small groups of 5-6 individuals. They are semi-aggressive and can be nippy, so carefully selecting tank mates is essential. Ideal companions include similarly sized, fast-swimming species that can hold their own, such as larger tetras, barbs, or rasboras. Avoid slow-moving or long-finned species.

These fish are omnivorous, with a preference for live foods such as brine shrimp, daphnia, and mosquito larvae. They will also accept high-quality flake or pellet foods and enjoy nibbling on algae and soft-leaved plants.

Rainbow Flagfish thrives in a well-planted aquarium with plenty of hiding spots, such as caves and driftwood. Floating plants can help diffuse light and create a more comfortable environment. Include low-light aquatic plants like Java Fern, Java Moss, or Anubias, and floating plants such as Water Sprite or Indian Fern.

Maintaining stable water parameters is essential for their health, so monitor the tank conditions regularly and perform partial water changes as needed. Moderate water flow and a suitable filtration system will help maintain a clean and stable environment.

The minimum aquarium size is 20 gallons, with an ideal community tank size of 30 gallons or more. Maintain a pH of 6.5-7.5, a hardness between 5-15 dGH, and a temperature range of 72-77°F (22-25°C).

Ensure the tank is securely covered, as these fish are known to jump.