Few creatures in the aquatic world captivate the imagination quite like the glass catfish (Kryptopterus vitreolus). With their nearly invisible bodies, delicate movements, and peaceful demeanor, these fish are living works of art. Whether you’re a seasoned aquarist or a beginner looking for a unique addition to your tank, the glass catfish offers a mesmerizing experience unlike any other.
We’ll explore everything you need to know about keeping these translucent wonders—from their natural habitat to their ideal tank conditions, diet, behavior, and even breeding tips.
What Is a Glass Catfish?
The glass catfish, also known as the ghost catfish or phantom catfish, is a small freshwater species native to the slow-moving rivers and streams of Thailand, Malaysia, and Indonesia. What sets them apart is their completely transparent body, allowing you to see their skeleton, internal organs, and even their beating heart!
- Scientific Name: Kryptopterus vitreolus
- Size: 3–4 inches (7–10 cm) when fully grown
- Lifespan: 5–7 years in optimal conditions
- Temperament: Peaceful, schooling fish
Unlike most catfish, which are bottom-dwellers, catfish prefer mid-water swimming, often hovering in a synchronized group. Their transparency isn’t just for show—it’s a natural camouflage mechanism, helping them evade predators in the wild.
Setting Up the Perfect Aquarium
Tank Size & Environment
Glass catfish thrive in well-planted, calm aquariums that mimic their natural habitat.
- Minimum Tank Size: 20 gallons (for a small school of 5–6 fish)
- Water Flow: Gentle filtration (they dislike strong currents)
- Substrate: Soft sand or fine gravel to prevent injury
- Decor: Driftwood, caves, and live plants (Java moss, Amazon sword, or floating plants)
Ideal Water Parameters
Maintaining stable water conditions is crucial for their health.
- Temperature: 75–80°F (24–27°C)
- pH Level: 6.0–7.5 (slightly acidic to neutral)
- Water Hardness: 5–12 dGH (soft to moderately hard)
- Lighting: Low to moderate (bright light can stress them)
Pro Tip: Use a dark background in the tank to enhance their transparency and make them stand out!
Diet & Feeding Habits
Catfish are omnivores, meaning they enjoy a varied diet. In the wild, they feed on small insects, larvae, and zooplankton. In captivity, their diet should include:
- Live & Frozen Foods: Brine shrimp, daphnia, bloodworms (their favorite!)
- High-Quality Pellets/Flakes: Sinking micro pellets or crushed flakes
- Occasional Vegetables: Blanched spinach or zucchini (for fiber)
Feeding Schedule:
- Offer small portions 2–3 times a day (they have small stomachs).
- Ensure food reaches mid-water since they rarely scavenge the bottom.
Warning: Overfeeding can pollute the water—remove uneaten food after 2–3 minutes.
Behavior & Social Needs
Schooling Nature
Glass catfish are highly social and must be kept in groups of at least 5–6. A lone glass catfish will become stressed, hide constantly, and may even die prematurely.
- Schooling Behavior: They swim in tight, synchronized groups.
- Active Times: Most active during dawn and dusk (crepuscular).
Tank Mates: Who Can Live with Glass Catfish?
Due to their peaceful nature, they do best with other calm, non-aggressive fish:
✅ Best Tank Mates:
- Small tetras (neon, ember, or rummynose)
- Rasboras (harlequin, chili)
- Dwarf gouramis
- Corydoras catfish
- Cherry shrimp & snails
❌ Avoid:
- Large, aggressive fish (cichlids, bettas with fin-nipping tendencies)
- Fast, competitive eaters (tiger barbs, danios)
Common Health Issues & Prevention
Despite their delicate appearance, glass catfish are hardy—if kept in proper conditions. Common health problems include:
1. Stress (Turning Cloudy or Hiding)
- Cause: Poor water quality, bright lighting, or lack of schooling mates.
- Solution: Maintain a group of 5+, dim lighting, and stable water parameters.
2. Ich (White Spot Disease)
- Symptoms: White dots on body, rapid breathing, rubbing against objects.
- Treatment: Raise temperature to 82°F (28°C) and use ich medication.
3. Fin Rot
- Symptoms: Frayed or discolored fins.
- Prevention: Clean water, avoid overcrowding.
Pro Tip: Quarantine new fish before adding them to prevent disease spread.
Breeding Glass Catfish: Is It Possible?
Breeding glass catfish in home aquariums is extremely rare but not impossible. Here’s what’s known:
- Conditioning: Feed high-protein live foods (bloodworms, brine shrimp).
- Breeding Tank: Soft, acidic water (pH 6.0–6.5), dim lighting, and fine-leaved plants.
- Spawning Behavior: Females scatter eggs among plants; adults should be removed afterward.
- Fry Care: Newly hatched fry are tiny—feed infusoria or liquid fry food.
Note: Most glass catfish in the trade are wild-caught due to breeding challenges.
Frequently Asked Questions (FAQs)
Q: Why is my glass catfish not moving much?
A: They may be stressed due to poor water conditions, lack of schooling mates, or bright lighting.
Q: Can glass catfish live with bettas?
A: Only if the betta is calm. Some bettas may mistake them for rivals.
Q: Do glass catfish need a heater?
A: Yes! They require stable tropical temperatures (75–80°F).
Q: How can I tell if my glass catfish is healthy?
A: A healthy glass catfish is active, has a clear body (no cloudiness), and eats eagerly.
Conclusion: Are Glass Catfish Right for You?
Glass catfish are stunning, peaceful, and fascinating fish that bring a touch of magic to any aquarium. However, they require:
✔ A well-maintained, planted tank
✔ A school of 5–6+ for mental well-being
✔ Gentle tank mates and proper feeding
If you can provide these conditions, you’ll be rewarded with one of the most unique and mesmerizing fish in the hobby.
Final Thought
Watching a school of glass catfish glide through the water is like observing living crystal sculptures—an experience every aquarist should enjoy at least once.
Would you like any additional details on a specific aspect of their care? Let me know how I can refine this guide further!