Compatibility Overview
Molly and Senegal Bichir are generally not recommended to be housed together. The issues listed above — whether water parameter incompatibility, predation risk, or aggression — create conditions where one or both fish are likely to suffer harm or chronic stress.
| Factor | Molly | Senegal Bichir | Verdict |
|---|---|---|---|
| Temperature | 72–82°F | 72–82°F | ✅ 72–82°F |
| pH Range | 7.5–8.5 | 6.5–7.5 | ⚠️ 7.5–7.5 (narrow) |
| Temperament | peaceful | aggressive | ❌ Risk |
| Adult Size | 4 in | 23.6 in | ❌ 6× difference |
| Min. Group | 3+ | 1+ | See below |
| Min. Tank Size | 100 gallons (for both species) | — | |
✅ Compatibility Positives
❌ Incompatibility Reasons
Species Profiles
Molly — Poecilia sphenops
Hardy livebearers that prefer alkaline, hard water — sometimes slightly brackish. Prolific breeders; peaceful community fish.
Senegal Bichir — Aquarium species
The Senegal Bichir is a fascinating freshwater fish known for its eel-like body and bony plates. It is a peaceful community fish that can be kept with a variety of species. These fish are active and require a spacious tank with plenty of swimming room. They are not known to be aggressive and can be a great addition to a beginner's aquarium.
Frequently Asked Questions
Can Molly live with Senegal Bichir?
Generally not recommended. Molly and Senegal Bichir are generally not recommended to be housed together. The issues listed above — whether water parameter incompatibility, predation risk, or aggression — create conditions where one or both fish are likely to suffer harm or chronic stress.
What tank size do I need for Molly and Senegal Bichir together?
A minimum of 100 gallons is recommended for keeping Molly and Senegal Bichir together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Molly and Senegal Bichir?
72–82°F
Is a Molly aggressive toward a Senegal Bichir?
Molly is peaceful and Senegal Bichir is aggressive. The adult size gap creates a meaningful predation risk.
Related Compatibility Guides
Compatibility score breakdown
The overall score is weighted across water chemistry, behavior, adult size, swimming zone, and social needs. A score is a planning aid—not a guarantee for individual fish.
| Factor | Score |
|---|---|
| Temperature | 100/100 |
| Ph | 0/100 |
| Temperament | 30/100 |
| Adult Size | 8/100 |
| Swim Zone | 68/100 |
| Social Needs | 92/100 |
Tank size scenarios
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 100 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 150 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 180 gal | Best when keeping larger schools or reducing territorial pressure. |