Neon Blue Rasbora
Neon Blue Rasbora (Sundadanio goblinus) is one of the most vivid nano fish available for the planted aquarium. A gleaming blue-green iridescent stripe runs the length of the body against a dark back, with a reddish to orange-red belly in well-conditioned individuals — a color combination that rivals the neon tetra for sheer intensity at nano scale. Despite being sold as a rasbora, this species belongs to the genus Sundadanio and is more closely related to danios.
Feeding & Care Tip: Start juveniles on Sera Micron Nature and transition to Sera Vipan Baby flakes as they mature. Supplement 2–3× per week with Hikari Frozen or Freeze-Dried Baby Brine Shrimp to enhance the vivid blue-green iridescence. Feed small amounts 2–3 times daily.
Native to blackwater streams and peat swamps in Sumatra and surrounding Indonesian islands, soft water, dark substrate, tannin additions, gentle filtration, and floating plants to diffuse lighting all contribute to the best expression of this fish's extraordinary color.
Keep in groups of at least eight, preferably twelve or more. Male Sundadanio in a large group display almost continuously, keeping the blue-green sheen at maximum intensity. This species is also notable for producing audible clicking or chirping sounds during male display.
The Neon Blue Rasbora in ideal blackwater conditions looks almost luminescent — a school appears to glow in the planted aquarium.
Care & Ideal Parameters
| Difficulty | Easy — Moderate |
| Temperament | Peaceful — Nano Community |
| Typical Adult Size | 0.7 inches (1.8 cm) |
| Min. Group Size | 8 minimum — groups of 12+ produce noticeably brighter iridescence |
| Ideal Temp | 68–79°F (20–26°C) |
| Ideal pH | 6.0–7.0 |
| Ideal GH | 1–5 dGH |
| Ideal KH | 0–3 dKH |
| Staple Food | Sera Micron Nature (juveniles); Sera Vipan Baby (adults) |
| Treat / Supplement | Hikari Frozen or Freeze-Dried Baby Brine Shrimp |
| Origin | Sumatra and surrounding Indonesian islands |
| Notes | Not a true rasbora — genus Sundadanio, related to danios. Sera Micron Nature for juveniles, Sera Vipan Baby for adults. Males produce audible chirping sounds. Very soft water preferred. |
