Ruby Tetra
Ruby Tetra
Ruby Tetra (Axelrodia riesei) is a tiny and vividly colored nano tetra — the ruby-red body of well-conditioned males is among the most intensely red colorations of any nano fish. Named in honor of Dr. Herbert Axelrod and Ramona Riesei. At under 1 inch it is a genuinely nano species.
Feeding & Care Tip: Hikari Micro Pellets (crushed or soaked) and Sera Vipan Baby make excellent daily staples. Supplement 2–3× per week with Hikari Frozen or Freeze-Dried Baby Brine Shrimp and Hikari Frozen Daphnia. Feed small amounts 2–3 times daily in a calm environment.
Native to the Rio Meta drainage in Colombia — blackwater streams with very soft, acidic water. A specialist blackwater nano species.
Keep in groups of at least 12. The ruby-red coloration is most intense in soft acidic water with tannins. Only with other nano species.
A specialist nano tetra — the ruby-red coloration in a properly conditioned male is extraordinary for a fish under an inch.
Care & Ideal Parameters
| Difficulty | Moderate |
| Temperament | Peaceful — nano blackwater specialist |
| Typical Adult Size | 0.9 inches (2.3 cm) |
| Min. Group Size | 12 minimum |
| Ideal Temp | 75–82°F (24–28°C) |
| Ideal pH | 5.0–6.8 |
| Ideal GH | 0–5 dGH |
| Ideal KH | 0–2 dKH |
| Staple Food | Hikari Micro Pellets (crushed/soaked); Sera Vipan Baby |
| Treat / Supplement | Hikari Frozen or Freeze-Dried Baby Brine Shrimp; Hikari Frozen Daphnia |
| Origin | Rio Meta drainage, Colombia |
| Notes | Named for Axelrod and Riesei. Vivid ruby-red coloration. Blackwater specialist. Under 1 inch. |
