Cardinal Rasbora
Cardinal Rasbora (Microrasbora rubescens) is one of the most jewel-like nano fish in the hobby. Males display a warm red to rose-red body with a brilliant iridescent blue-green lateral stripe — a color combination calling to mind the Cardinal Tetra but in a smaller, more delicate package. Endemic to Myanmar's Inlé Lake region.
Feeding & Care Tip: Start juveniles on Sera Micron Nature and transition to Sera Vipan Baby flakes as they grow. Supplement 2–3× per week with Hikari Frozen or Freeze-Dried Baby Brine Shrimp. Feed small amounts 2–3 times daily. Benefits from very stable, clean conditions.
Native to the Inlé Lake drainage in Shan State, Myanmar, this species inhabits clear, moderately soft to slightly hard water at higher altitude. Unlike most nano rasboras, it prefers slightly cooler temperatures and cannot tolerate extreme blackwater conditions.
Keep in groups of at least eight, preferably twelve or more. A gentle, somewhat timid fish that does best with other small, peaceful species that enjoy similar water conditions.
A remarkable fish for its size — the combination of red body and blue stripe is striking and unusual. Its rarity in the hobby makes it a genuine collector's item.
Care & Ideal Parameters
| Difficulty | Moderate |
| Temperament | Peaceful — Nano Community |
| Typical Adult Size | 1.0 inch (2.5 cm) |
| Min. Group Size | 8 minimum — groups of 12+ produce noticeably brighter color |
| Ideal Temp | 68–75°F (20–24°C) |
| Ideal pH | 6.5–7.5 |
| Ideal GH | 3–10 dGH |
| Ideal KH | 2–6 dKH |
| Staple Food | Sera Micron Nature (juveniles); Sera Vipan Baby (adults) |
| Treat / Supplement | Hikari Frozen or Freeze-Dried Baby Brine Shrimp |
| Origin | Inlé Lake drainage, Myanmar |
| Notes | Endemic to Inlé Lake, Myanmar. Prefers cooler, clearer water than most nano rasboras. Sensitive to poor water quality. Rare in the trade. Sera Micron Nature for juveniles, Sera Vipan Baby for adults. |
