The Emerald Dwarf Rasbora (Danio erythromicron) is a distinctive freshwater aquarium fish valued for its appearance and behaviour. It is native to Lake Inle and nearby waters in Myanmar, where it lives among dense vegetation in clear, shallow water. Understanding its small natural habitat details helps aquarists provide the right flow, cover, food and tank mates.

Emerald Dwarf Rasbora Size and Aquarium Setup

Adults reach about 2–3 cm (0.8–1.2 inches). A planted 38-litre (10-gallon) tank is suitable for a group, but a larger footprint makes it easier to keep a proper shoal. Keep at least eight, and preferably ten or more. The aquarium should be fully cycled before the fish are added, and routine partial water changes should be used to keep nitrate and dissolved waste under control.

  1. Use a mature, fully cycled aquarium.
  2. Provide cover as well as open swimming or feeding space.
  3. Match filtration strength to the species’ natural habitat.
  4. Prevent sudden changes in temperature or water chemistry.

Water Conditions

Recommended conditions are 20–25°C (68–77°F), pH 7.0–8.0, with moderate hardness. They prefer clean, oxygenated water and do not appreciate sudden swings. Always acclimate new fish gradually and test ammonia, nitrite and nitrate, especially during the first weeks after introduction.

Diet and Feeding

The Emerald Dwarf Rasbora should be fed small flakes, micro pellets, daphnia, cyclops, baby brine shrimp and other tiny frozen or live foods. Offer portions that can be eaten promptly, vary the diet through the week and remove uneaten food before it affects water quality.

Sexing Emerald Dwarf Rasbora

Males display stronger blue-green bars and reddish fins, while females are rounder through the abdomen and usually less intensely coloured. Juveniles can be difficult to sex, so differences may only become clear as the fish mature.

Breeding

This species is an egg scatterer. Condition adults with live foods, then place a pair or small group over moss, fine plants or a mesh base. Remove the adults after spawning because they may eat eggs and fry. Consistent feeding and very clean water are usually more important than frequent handling or major changes to the aquarium.

Is It Good for a Community Tank?

Real Reef Canada

Shy but peaceful. Suitable companions include Pygmy Corydoras, small peaceful danios and gentle shrimp. Avoid boisterous fish that dominate food or make the rasboras hide.

Species Variations and Albino Forms

Colour intensity varies with mood, diet, sex and lighting. There is no common, stable albino form in the aquarium trade. Do not confuse this fish with the similarly sized Celestial Pearl Danio, which has spots rather than vertical bars.

Ease of Care

Care level: Beginner to intermediate. Success depends on choosing healthy stock, avoiding overcrowding and ensuring every fish receives suitable food. Observe the group daily for clamped fins, unusual hiding, rapid breathing or weight loss.

Frequently Asked Questions

How many Emerald Dwarf Rasbora should be kept together?

Follow the species’ social needs described above and provide enough room for natural displays, feeding and escape from dominant individuals. A proper group usually produces more confident behaviour than keeping only one or two schooling fish.

Can Emerald Dwarf Rasbora live in a beginner aquarium?

The listed care rating is a useful guide, but even beginner-friendly fish need a cycled tank and stable water. Species rated intermediate often have special feeding, flow or social requirements that should be prepared before purchase.

What is the best way to introduce Emerald Dwarf Rasbora?

Dim the aquarium lights, acclimate gradually, and release the fish near cover. Feed lightly on the first day and watch existing tank mates for chasing or food competition.