Phoenix Rasbora — Sunken Belly
Home/Aquarium Fish Diseases/Phoenix Rasbora/Sunken Belly
⚠️ Urgent · physical

Why Is My Phoenix Rasbora Sunken Belly?

Boraras merah
🐟 Species: Phoenix Rasbora
🔬 Problem: Sunken Belly
📋 Category: physical
⚡ Urgency: urgent

Sunken belly in Phoenix Rasbora, Boraras merah, is a serious condition indicating malnutrition or internal issues. It can lead to weakened immune systems and is an urgent concern. Owners should first ensure proper water parameters and diet before seeking veterinary assistance.

Common Causes of Sunken Belly in Phoenix Rasbora

Poor Diet

Most Likely

Inadequate nutrition or overfeeding can lead to malnutrition.

Internal Parasites

Possible

Parasitic infections can cause internal damage and weight loss.

Bacterial Infections

Possible

Bacteria such as Aeromonas can cause internal inflammation and weight loss.

Stress

Possible

Stress from tankmates or environmental changes can lead to decreased appetite and weight loss.

Genetic Factors

Less Common

In some cases, sunken belly may be due to genetic predisposition.

How to Diagnose

Follow these steps in order. Stop when you identify a likely cause and move to treatment.

  1. Observe the fish's behavior and appearance for any other signs of illness.

    Look for signs of aggression, loss of color, or other abnormal behaviors.

  2. Check water parameters for ammonia, nitrite, nitrate, pH, and temperature.

    Ensure they are within the optimal range for Phoenix Rasbora.

    Recommended: Water test kit
  3. Perform a physical examination of the fish, looking for any external parasites or wounds.

    Use a magnifying glass to inspect the fish's body closely.

    Recommended: Magnifying glass
  4. Consider a fecal float test to check for internal parasites.

    This test can identify parasites that may be causing the condition.

    Recommended: Fecal float kit
  5. If necessary, consult with a vet for a more detailed examination or to rule out other conditions.

    Vets may perform additional tests such as a blood test or ultrasound.

How to Fix It

  1. Adjust the diet to include high-quality, varied food options.

    Provide small, frequent feedings of flakes, pellets, and live or frozen foods.

  2. Perform regular water changes to maintain optimal water quality.

    Change 20-30% of the water weekly.

  3. Treat for internal parasites if detected, following the vet's instructions.

    Use appropriate medications as prescribed.

  4. Ensure the tank environment is stress-free, with adequate hiding spots and tankmates that are compatible with the Phoenix Rasbora.

    Monitor tank conditions and remove any aggressive or bullying fish.

  5. If the condition persists, consult a vet for further treatment options.

    Vets may prescribe antibiotics or other medications for bacterial infections.

Prevention

Prevent sunken belly by maintaining optimal water conditions, feeding a balanced diet, and minimizing stress in the tank.

When to Seek Expert Help

See a vet if: Seek veterinary assistance immediately if the fish shows signs of sunken belly, as it can be a sign of a serious underlying condition.

📖 Full Care Guide

Learn everything about keeping a healthy Phoenix Rasbora — tank setup, water parameters, diet, tank mates, and disease prevention.

Phoenix Rasbora Care Guide →

🔬 AI Symptom Checker

Not sure what's wrong? Describe your fish's symptoms to the FishCare AI and get an instant diagnosis.

Check Symptoms →

Frequently Asked Questions

✓
Editorial review

This guide was reviewed for biological accuracy and practical aquarium care guidance. Always test water parameters before treating a sick fish — poor water quality is the most common root cause. Consult an aquatic veterinarian if symptoms persist after 48 hours of correct treatment.