Emperor Tetra ( Nematobrycon palmeri ) is one of the most elegant and regal-looking tetras available. Males develop extraordinary extended fin rays on the central caudal fin forming a distinctive trident tail, deep purple to violet iridescence on the body, and the most striking feature: vivid turquoise-blue eyes that glow with an intensity unlike any other tetra. Named for H.C. Palmer who collected the first specimens from the San Juan River drainage in Colombia.
Feeding & Care Tip: Sera Vipan Tropical Flakes and Hikari Micro Pellets make excellent daily staples. Supplement 2-3× per week with Hikari Frozen or Freeze-Dried Bloodworms , Hikari Frozen or Freeze-Dried Baby Brine Shrimp , or Hikari Vibra Bites . Feed small amounts 2-3 times daily.
Native to the San Juan and Atrato River basins in Colombia — Pacific-slope rivers draining the western Andes. Considerably more adaptable than many Colombian tetras, thriving across a wide pH range without the strict blackwater demands of Rio Negro species. One of the more beginner-accessible Colombian tetras.
Keep in groups of at least 6 with multiple females per male. Males display constantly with fin-spreading territorial displays — in a mixed-sex group with adequate space, this near-constant performance is spectacular. Males in peak condition with full fin extensions and maximum purple iridescence are genuinely breathtaking.
Excellent for planted aquariums — the relatively subdued base coloration means it relies on iridescence and fin development. Best against a dark background with subdued lighting that picks up the purple sheen and turquoise eye glow.
| Difficulty | Easy |
| Temperament | Peaceful — males territorial with each other |
| Typical Adult Size | 2.0 inches (5 cm) |
| Min. Group Size | 6 minimum — mixed sexes |
| Ideal Temp | 73-81°F (23-27°C) |
| Ideal pH | 6.0-7.5 |
| Ideal GH | 3-12 dGH |
| Ideal KH | 1-6 dKH |
| Staple Food | Sera Vipan Tropical Flakes; Hikari Micro Pellets |
| Treat / Supplement | Hikari Frozen or Freeze-Dried Bloodworms; Hikari Frozen or Freeze-Dried Baby Brine Shrimp; Hikari Vibra Bites |
| Origin | San Juan and Atrato River basins, Colombia (Pacific slope) |
| Notes | Males: trident tail extensions, purple iridescence, turquoise eyes. Named for collector H.C. Palmer. Pacific-slope Colombia. Male territorial displays spectacular in mixed groups. |