The Galaxy Rasbora, also known as Celestial Pearl Danio or by its scientific name Danio margaritatus, is a captivating freshwater fish that has rapidly gained popularity in the aquarist community. Discovered in 2006 in Myanmar, this diminutive species is renowned for its stunning coloration and peaceful demeanor, making it a stellar addition to small and community tanks alike.

Overview and Appearance:
- Scientific Name: Danio margaritatus
- Family: Cyprinidae
- Size: 0.75-1 inch (2-2.5 cm)
- Lifespan: 3-5 years in optimal conditions

Galaxy Rasboras are adorned with a deep blue to black body, speckled with sparkling spots that resemble a starry night sky, giving them their celestial moniker. Their fins are subtly touched with red or orange hues, adding to their vibrant allure. The males are generally more brightly colored and have a slightly slimmer body shape compared to the females.

Habitat and Tank Requirements:
These celestial beauties thrive in environments that mimic their natural habitat:
- Water Parameters: Soft, slightly acidic to neutral water (pH 6.5-7.5), with a temperature range of 73-79°F (23-26°C).
- Tank Setup: A densely planted aquarium with dark substrate to highlight their colors. Driftwood, rocks, and leaf litter can create a natural and comforting environment. Gentle filtration and water movement are crucial as they originate from calm, shallow waters.
- Tank Size: A minimum of 10 gallons is suggested, though larger is preferable to provide ample space for schooling behavior.

Diet and Nutrition:
Galaxy Rasboras are omnivorous and will accept a variety of foods:
- Small, high-quality flake food or micro pellets as the staple diet.
- Regular servings of live or frozen foods like daphnia, brine shrimp, or micro worms to promote health and color vibrancy.
- Occasional vegetable matter or algae-based foods to ensure a balanced diet.

Behavior and Compatibility:
Galaxy Rasboras are peaceful, schooling fish that thrive in groups of 6 or more. Their tranquil nature makes them perfect for community tanks with other non-aggressive species. Ideal tank mates include:
- Other small, peaceful fish like Neon Tetras or Harlequin Rasboras.
- Gentle bottom dwellers such as small Corydoras or Otocinclus.
- Dwarf shrimp like Cherry or Amano shrimp, which can share the tank without fear of predation.

Breeding:
Breeding Galaxy Rasboras can be a delightful experience. They scatter their eggs among fine-leaved plants or moss. The water should be soft and slightly acidic. It's recommended to use a breeding tank to protect the eggs and fry from being eaten. After spawning, adults should be removed. The fry are tiny and require infusoria or liquid fry food initially, graduating to micro worms or baby brine shrimp as they grow.

Galaxy Rasboras are like a microcosm of the night sky, bringing awe and tranquility to the aquatic world. Their serene nature and mesmerizing appearance make them an excellent choice for both novice and experienced aquarists. By providing them with a suitable habitat, appropriate tank mates, and a balanced diet, these celestial swimmers will thrive and bring a touch of the cosmos to any aquarium, proving that sometimes the most profound beauty comes in the smallest packages.