Gertrudae (Butterfly Rainbow)

The Gertrudae, commonly known as the Butterfly Rainbow or Gertrude's blue-eye, is a stunning freshwater fish belonging to the family Pseudomugilidae. This species is renowned for its vibrant coloration and unique iridescent scales, which can display shades of blue, yellow, and green depending on the light. Native to Indonesia, Papua New Guinea, and northern Australia, the Gertrudae typically inhabits slow-moving freshwater streams and swamps, where it thrives among dense vegetation and submerged structures.

In terms of appearance, the Gertrudae features a streamlined body with a distinctive blue spot on its dorsal fin and a strikingly beautiful blue eye, which gives it the common name 'blue-eye.' Adult specimens reach a maximum size of about 5 cm, making them suitable for smaller aquariums. Their peaceful demeanor and captivating display behaviors, including schooling and gentle fin displays, make them an ideal choice for community tanks.

Behaviorally, Gertrudae are active swimmers that prefer to inhabit the upper levels of the aquarium. They are social fish that thrive in groups, so it is recommended to keep them in schools of at least six individuals. This species exhibits interesting breeding behaviors, often laying eggs among fine-leaved plants, which adds an engaging aspect to their care in a home aquarium.

In their natural habitat, Gertrudae are often found in densely vegetated areas, where they feed on small invertebrates and organic detritus. Their adaptability to various freshwater conditions makes them resilient and easy to care for, appealing to both novice and experienced aquarists alike.

To ensure the optimal health of Gertrudae, maintain water temperatures between 24°C and 28°C, with a pH range of 6.5 to 7.5. Water hardness should be kept at 5 to 15 dGH. A well-filtered aquarium with plenty of plants and swimming space will mimic their natural habitat and encourage natural behaviors. Provide regular water changes to maintain water quality, ideally 10-20% weekly.

Feeding Gertrudae is straightforward; they are omnivorous and thrive on a varied diet that includes high-quality flakes, micro-pellets, and live or frozen foods such as daphnia and brine shrimp. Regular feeding of small amounts two to three times a day will promote healthy growth and coloration.

In terms of compatibility, Gertrudae are peaceful and can be housed with a variety of community fish. Avoid aggressive species that may stress them. When introducing new fish, acclimate them slowly to prevent shock, ideally using the drip acclimation method. Quarantine new arrivals for at least two weeks to ensure they are free from disease before adding them to the main tank.

Gertrudae are suitable for shipping due to their hardiness in transit. They should be packed in appropriate density, ideally with 1-2 fish per liter of water. Maintain shipping temperatures between 22°C and 26°C to prevent stress and ensure their safe arrival. As a non-CITES species, Gertrudae do not require special export permits, simplifying the shipping process for wholesalers and importers.