Walking Catfish (Clarias batrachus)

The walking catfish is a unique freshwater fish known for its ability to move on land. This hardy species requires special care but can be a fascinating addition for experienced aquarists.

Overview

The walking catfish (Clarias batrachus) is a freshwater fish native to Southeast Asia. This species is notable for its ability to move short distances on land using its pectoral fins. Thanks to a specialized suprabranchial organ, the walking catfish can breathe atmospheric air, allowing it to survive in low-oxygen environments.

The fish has an elongated body covered in a slimy coating and can grow up to 50 cm in aquarium conditions. Its coloration ranges from gray to brown with spots, which helps it blend into its natural environment.

Fun Fact: In some regions, the walking catfish is considered an invasive species due to its ability to thrive in various conditions, including polluted waters.

Aquarium Requirements

The walking catfish is a large and active fish, so a spacious aquarium is essential for its well-being.

• Tank Size: Minimum 200 liters for a single fish. For a group or community tank, a volume of 300 liters or more is recommended.
• Water Parameters:
  • Temperature: 22-28°C
  • pH: 6.5-8.0
  • Hardness (GH): 5-20
• Lighting: Dim lighting is preferred, as the fish thrives in low-light conditions.
• Decor: Plenty of hiding spots (driftwood, caves, ceramic pipes) and dense vegetation.
• Lid: A tight-fitting lid is mandatory, as the walking catfish can escape from the tank.

Tip: Use a powerful external filter, as this species produces a significant amount of waste.

Diet and Feeding

The walking catfish is an omnivorous species that feeds on insects, small fish, crustaceans, and plant matter in the wild. In an aquarium, its diet should be varied:

• Staple Food: High-protein sinking pellets for catfish.
• Supplemental Foods:
  • Live or frozen foods (bloodworms, brine shrimp, shrimp).
  • Vegetables (cucumber, zucchini, spinach).
• Feeding Frequency: 1-2 times a day, preferably in the evening, as the fish is nocturnal.

Important: Avoid overfeeding to prevent water quality issues and health problems.

Care and Maintenance

The walking catfish is a hardy species but requires stable water conditions.

• Water Changes: Weekly water changes of 25-30% of the tank volume.
• Filtration: A powerful filtration system with mechanical and biological filtration.
• Aeration: While the fish can breathe air, proper aeration is necessary for the well-being of other tank inhabitants.
• Water Testing: Regularly check ammonia, nitrite, and nitrate levels.

Tip: Use a gravel vacuum to clean the substrate, as catfish produce a lot of waste.

Compatibility

The walking catfish is semi-aggressive and territorial, especially as it matures. When choosing tankmates, consider the following:

• Suitable Tankmates:
  • Large cichlids (e.g., Oscars, Severums).
  • Other large catfish (Plecos, Synodontis).
  • Large barbs or rainbowfish.
• Unsuitable Tankmates:
  • Small fish (neons, guppies, danios), as they may become prey.
  • Slow-moving or delicate species (angelfish, discus).

Important: Monitor the fish's behavior, especially after introducing new tankmates.

Breeding

Breeding walking catfish in captivity is challenging and requires experience.

• Breeding Conditions:
  • A separate breeding tank of at least 100 liters.
  • Water temperature: 26-28°C.
  • Soft water (pH 6.5-7.0, GH 5-10).
  • Hiding spots and plants.
• Breeding Process:
  • The male builds a bubble nest at the water's surface.
  • The female lays eggs, which the male guards.
• Fry Care:
  • After hatching, move the fry to a separate tank.
  • Feed the fry with infusoria, baby brine shrimp, and crushed pellets.

Tip: If you're a beginner, start with keeping adult fish before attempting breeding.

Common Issues and Solutions

1. Fish Attempting to Escape:

• Ensure the tank has a tight-fitting lid.
• Check water parameters, as discomfort may cause this behavior.

2. Aggressive Behavior:

• Make sure the tank is large enough.
• Check if the tank is overcrowded.

3. Loss of Appetite:

• Test water quality.
• Offer a more varied diet.

Conclusion

The walking catfish is a remarkable fish that can be a fascinating addition to an experienced aquarist's tank. However, its care requires attention to detail, a spacious aquarium, and proper maintenance. If you're prepared to meet its needs, the walking catfish will become a unique and captivating inhabitant of your aquarium.