Asian Swamp Eel (Monopterus albus)

Asian Swamp Eel — Monopterus albus

Serpentine survivor with raw instinct

The Asian Swamp Eel is a primitive, air-breathing predator built for survival. Long, cylindrical, and scaleless, Monopterus albus resembles a living river serpent more than a traditional fish. Its coloration ranges from muddy brown to olive-gray, sometimes with mottled patterning, allowing it to blend perfectly into murky substrates and vegetation.

Native to swamps, rice paddies, and slow-moving waters throughout Southeast Asia, this species is famous for its ability to survive in low-oxygen environments. It possesses specialized respiratory adaptations that allow it to gulp atmospheric air, making it incredibly hardy when housed correctly. In the aquarium, it spends much of its time partially buried or tucked into tight hiding spaces, emerging at night to hunt.

Growing to 24–36+ inches, the Asian Swamp Eel is a powerful ambush predator that requires secure housing and experienced care.

Aquarium Setup

• Minimum Tank Size: 180–240 gallons (larger preferred long-term)

• Substrate: Deep sand layer (allows burrowing behavior)

• Flow: Low to moderate

• Décor: PVC tunnels, driftwood, tight caves, and hiding structures

• Lighting: Dim to moderate

• Cover: Extremely secure lid required — expert escape artist

• Filtration: Strong biological filtration essential

Tank Mates

Best kept alone or with very large, robust species:

• Large catfish

• Datnoids

• Giant gouramis

• Large cichlids

Avoid small fish — they will be eaten. Avoid aggressive species that may stress the eel.

Water Parameters

• Temperature: 75–86°F (24–30°C)

• pH: 6.0–7.5

• Hardness: Soft to medium

• Water Quality: Clean and stable conditions required

Diet

Strict carnivore:

• Fish fillet

• Shrimp and prawn

• Earthworms

• High-protein sinking pellets (once trained)