Colomesus Asellus (Amazon Puffer) – The Perfect Freshwater Puffer for Community Tanks
The Amazon Puffer (Colomesus asellus) is a vibrant, intelligent freshwater pufferfish with a playful personality. Ideal for experienced aquarists, it thrives in well-maintained tanks with the right care.

Detailed Description

• Scientific Name: Colomesus asellus

• Common Names: Amazon Puffer, South American Puffer (SAP)

• Size: Up to 3 inches (7.5 cm)

• Lifespan: 8–10 years with proper care

• Temperament: Semi-aggressive, active, and curious

• Tank Level: Mid to top-dweller

Water Conditions

Amazon Puffers require stable water parameters to stay healthy. Being sensitive to poor water quality, they demand a well-filtered and clean environment.

• Tank Size: Minimum 30 gallons for a small group (3+ puffers)

• Temperature: 74–82°F (23–28°C)

• pH: 6.5–7.5

• Water Hardness: Soft to moderately hard (5–15 dGH)

• Filtration: Strong filtration is essential; puffers produce a high bioload

• Flow: Moderate water movement mimicking river currents

• Substrate: Sand or fine gravel preferred to prevent injuries

Tank Setup & Decor

Amazon Puffers are active swimmers that appreciate an environment mimicking their natural Amazonian habitat.

• Provide driftwood, rocks, and dense plants to create hiding spots and reduce stress.

• Open swimming spaces are important to allow their natural curiosity and activity to shine.

• A well-oxygenated tank is beneficial, so consider an air stone or additional aeration.

Tank Mates

Unlike most puffers, Amazon Puffers can cohabit with other fish if carefully chosen. However, their fin-nipping tendencies make tankmate selection crucial.

Compatible Tank Mates:
✔️ Fast-moving, robust fish like danios, rasboras, or tetras
✔️ Bottom-dwellers such as corydoras and loaches
✔️ Larger, peaceful fish like angelfish or gouramis

Avoid:
❌ Long-finned species like bettas and guppies (may be nipped)
❌ Slow-moving fish that may be outcompeted for food
❌ Aggressive or territorial fish that may stress the puffer

Feeding & Diet

Amazon Puffers are carnivorous with a specialized diet that requires proper planning. They have ever-growing teeth that need hard-shelled foods to prevent overgrowth.

• Staple Diet:

  • Snails (ramshorn, pond snails) – crucial for maintaining teeth

  • Frozen or live bloodworms, brine shrimp, and blackworms

  • Small crustaceans like mysis shrimp

  • Occasionally, high-quality sinking pellets or gel foods

• Feeding Frequency:

  • 2–3 times daily in small portions

  • Vary diet to ensure proper nutrition and dental health

Care & Maintenance

• Perform weekly water changes (30–50%) to keep ammonia and nitrite levels at zero.

• Monitor teeth growth—if puffers stop eating, they may need manual dental trimming (best left to experts).

• Watch for stress signs like excessive hiding, fin damage, or loss of appetite.

• Quarantine new fish before introducing them to prevent disease transmission.

Why Choose an Amazon Puffer?

• Unique personality and intelligence, often recognizing their owners.

• One of the few freshwater puffers suitable for community setups.

• Rewarding to keep for aquarists willing to meet their care needs.

Conclusion
The Amazon Puffer (Colomesus asellus) is a fascinating fish for dedicated aquarists. While not beginner-friendly, its quirky behavior, vibrant colors, and interactive nature make it an outstanding addition to a well-maintained aquarium. With proper care, a balanced diet, and compatible tank mates, these little puffers will thrive and bring joy to any freshwater setup.