Emerald Dwarf Rasbora

Celestichthys erythromicron comes from Inle Lake in Myanmar, a shallow, heavily vegetated lake known for its alkaline, moderately hard water and cool conditions. At just 2 cm full grown, it's one of the smallest members of the danionin group and a close relative of the wildly popular Celestial Pearl Danio.

Up close, these fish are genuinely stunning. A blue-green iridescent base is crossed by a series of thin, dark vertical bars, and the fins glow with warm orange tones that catch light beautifully under a good planted tank fixture.

They do best in neutral to slightly alkaline water with moderate hardness and prefer cooler temperatures than most tropical fish kept in the hobby. Anywhere in the low-to-mid 20s Celsius keeps them healthy and active. A mature, heavily planted tank is really where they shine. Dense vegetation gives them hiding spots they'll actually use, and once they feel secure they spend much more time out in the open. A fine-leaved carpet, some floating plants, and a dark substrate all help enormously.

Feeding is easy enough since they accept high-quality micro pellets, crushed flakes, and small frozen or live foods like baby brine shrimp and daphnia. Because of their tiny mouths, food size matters more than most people expect. Oversize food gets ignored or spat out.

These are a species that rewards patience. A quiet tank, a big enough school, and the right parameters will eventually produce confident fish that display their barring and fin color properly. Sparse, noisy community setups produce shy, washed-out fish that hide constantly. Browse tank builds featuring this species and you'll see why they've developed a passionate following among nano planted tank enthusiasts.