Can Emperor Tetra live with Foxface Rabbitfish?
These two species are usually compatible in community tanks.
Why Emperor Tetra and Foxface Rabbitfish Work
These two species overlap in both temperature (74–82°F overlap) and pH (- overlap range). Their temperature tolerances are close enough, and neither fish pushes the pH so far outside the other's comfort zone that it creates chronic stress. The temperament match (peaceful + peaceful) is low-conflict. In a 75+ gallon tank with adequate hiding spots, these two can coexist with minimal problems.
Emperor Tetra
Nematobrycon palmeri
| Adult Size: | 2.0" |
| Temperament: | peaceful |
| Min Tank: | 20 gal |
| Temperature: | 73-82°F |
| pH Range: | 5.5-7.0 |
Foxface Rabbitfish
Siganus vulpinus
| Adult Size: | 9.0" |
| Temperament: | peaceful |
| Min Tank: | 75 gal |
| Temperature: | 74-82°F |
| pH Range: | 8.1-8.4 |
Water Parameter Overlap
| Parameter | Emperor Tetra | Foxface Rabbitfish | Overlap |
|---|---|---|---|
| Temperature | 73-82°F | 74-82°F | 8°F ✓ |
| pH | 5.5-7.0 | 8.1-8.4 | No overlap ✗ |
Compatibility Breakdown
Temperament Match: peaceful + peaceful. Both peaceful → minimal conflict.
⚠️ Size Predation Risk: Emperor Tetra (2.0") vs Foxface Rabbitfish (9.0"). A 7.0" gap — the larger fish will view the smaller fish as food.
Score: 80/100 (GOOD ≥80, CAUTION ≥50, RISKY <50).
🔧 Tank Setup Requirements (for Both)
- Minimum tank: 75 gallons — sized for the larger fish in the pair.
- Temperature: keep it between 74°F and 82°F.
- pH: no shared range. One species will be outside its tolerance regardless of what you set.
- Hiding spots: essential for Emperor Tetra — caves, plants, or driftwood to retreat when feeling stressed.
- Water changes: 25% weekly minimum. Two species mean double the bioload.
🔧 Tank Stocking Calculator
Enter tank size to calculate safe stocking levels:
Recommended Equipment
Based on tank size 75+ gallons:
Dried seaweed sheets for marine herbivores
Explore Related Checks
See what else works with these fish:
⚠️ Common Reasons This Pairing Fails in Practice
- Size-based predation: The 7.0" size gap means the larger fish may eat the smaller one once it grows to full size. This is not fixable with more hiding spots.
- Overcrowding: Even compatible species fail in tanks that are too small. Double the species means double the bioload — 25% weekly water changes are the minimum.
- Inadequate acclimation: Adding both species on the same day without quarantine is a common mistake. Always drip-acclimate new arrivals and quarantine for 2–4 weeks.
- Mismatched feeding: Emperor Tetra is a omnivore while Foxface Rabbitfish is a herbivore. Use targeted feeding zones and sinking vs. floating food to ensure both get proper nutrition.
Tools & Resources
Accuracy note: This tool uses expert rules + FishBase.org data. Individual fish behavior varies — a peaceful individual Emperor Tetra may act differently from its species average. Always observe, quarantine new arrivals for 2-4 weeks, and avoid overcrowding. If a pairing says CAUTION, start with a smaller group and a lid.