Emerald Rasbora (Microrasbora erythromicron)

Emerald Rasbora (Microrasbora erythromicron)

The Emerald Rasbora, also known as the Emerald Dwarf Rasbora, is a small, vibrant freshwater fish native to Myanmar. It is admired for its iridescent emerald-green body, horizontal orange stripes, and peaceful nature. This species thrives in nano and planted aquariums, making it a popular choice for aquarists seeking a stunning addition to their tank.

Natural Habitat

Emerald Rasboras are found in Lake Inle, a high-altitude freshwater lake in Myanmar. These waters are clear, cool, and rich in vegetation, providing a unique environment with slightly alkaline water conditions.

Aquarium Care

Tank Requirements

• Minimum Tank Size: 20 liters for a small group (6–8 individuals).
• Water Temperature: 22–26°C.
• pH Range: 6.5–8.0 (slightly alkaline water preferred).
• Water Hardness: 5–15 dGH (soft to moderately hard water).
• Filtration: Gentle flow; sponge filters or low-flow external filters are ideal.

Aquascaping

• Substrate: Sand or fine gravel to replicate their natural environment.
• Decor: Include driftwood, smooth rocks, and caves for hiding spots.
• Plants: Dense planting with species like Java Moss, Cryptocoryne, Dwarf Hairgrass, and floating plants such as Salvinia or Duckweed provides cover and security.
• Lighting: Moderate lighting enhances their iridescent green and orange coloration.

Tank Mates

Emerald Rasboras are peaceful and best suited for nano or community tanks with similarly gentle species. Suitable companions include:

• Other small rasboras, tetras, or pencilfish.
• Bottom-dwellers like pygmy Corydoras or shrimp species like cherry or Amano shrimp.
  Avoid: Large or aggressive fish that may intimidate or outcompete them.

Feeding

Emerald Rasboras are omnivorous and require a varied diet:

• Staple Foods: High-quality micro-pellets or finely crushed flakes suitable for small fish.
• Protein: Live or frozen foods like brine shrimp, daphnia, and mosquito larvae.
• Vegetable Matter: Occasionally include spirulina-based foods or blanched vegetables.
  Feed small portions 1–2 times daily, ensuring all fish receive food.

Behavior and Personality

• Activity: Active swimmers that occupy the middle and upper levels of the tank.
• Social Behavior: They are shoaling fish and should be kept in groups of at least 6 to promote natural behavior and reduce stress.
• Temperament: Peaceful and shy, they thrive in a calm, well-planted environment.

Breeding

Breeding Emerald Rasboras is achievable with proper care and conditions.

Sexing

• Males: More vibrant with brighter green coloration and pronounced orange stripes.
• Females: Slightly larger and rounder, particularly when carrying eggs.

Breeding Tank Setup

• A separate breeding tank of at least 10 liters with soft, slightly alkaline water (pH 7.0–8.0) is recommended.
• Include fine-leafed plants or spawning mops for egg deposition.

Breeding Process

1. Condition the breeding pair with high-quality live or frozen foods.
2. Males court females by intensifying their colors and performing display behaviors.
3. Eggs are scattered among plants and hatch within 24–36 hours.

Fry Care

• Feed fry infusoria or liquid fry food initially.
• Transition to baby brine shrimp or powdered fry food as they grow.

Key Notes

• Water Quality: Emerald Rasboras are sensitive to poor water conditions, so regular water changes are essential.
• Behavior: A well-planted tank with subdued lighting and plenty of hiding spots helps them feel secure.
• Group Size: Larger groups enhance their natural schooling behavior and reduce shyness.

The Emerald Rasbora (Microrasbora erythromicron) is a dazzling species that brings vibrant color and peaceful energy to nano and community aquariums. Its manageable size, striking appearance, and easy care make it an excellent choice for aquarists of all levels.