Asian Swamp Eel

Monopterus albus is one of the most ecologically successful eel-like fish in the world, distributed across a vast range from China through Southeast Asia and introduced to parts of North America and Hawaii. Its capacity for air-breathing, aestivation in dry mud, and even sequential hermaphroditism make it one of the most remarkable vertebrates kept by aquarists.

In the aquarium this species requires a deep, soft substrate, minimal decor that could impede its burrowing, and an absolutely escape-proof lid. It is powerful enough to dislodge poorly secured covers. Water temperature range is broad, making it suitable for slightly cooler conditions than most tropical species.

All meaty foods are consumed eagerly: earthworms, prawns, frozen fish flesh, and large frozen bloodworm. It is highly predatory and should be kept only with fish too large to be consumed, ideally in a species-only setup or with only very large robust companions.

Water: Adaptable, pH 6.0–8.0, temperature 15–28°C, GH 3–20, KH 1–12. Tank: Minimum 200 L, deep muddy or sandy substrate, powerfully secured lid. Feeding: Carnivore; earthworms, prawns, frozen fish flesh, and large bloodworm. Breeding: Hermaphroditic; nests built from bubbles among surface vegetation in the wild. Compatibility: Species tank recommended; extremely predatory toward smaller fish.