Misgurnus anguillicaudatus is a large, elongated loach with a cylindrical, eel-like body, small eyes, and multiple pairs of sensory barbels around its small, downturned mouth. Native to ponds, slow streams, rivers, and rice paddies across China, Japan, and Korea, it is a cold-water to cool temperate species that thrives at temperatures well below those required by most tropical fish.
The Dojo Loach is famous in East Asian folklore and among aquarists for its reputed ability to predict weather changes: as atmospheric pressure drops before storms, the fish becomes unusually active, darting and wriggling near the surface. This behavior is caused by its intestinal breathing adaptation — like all cobitid loaches, it can supplement gill breathing by gulping air and absorbing oxygen through its gut lining.
Reaching up to 30 cm in large aquariums, the Dojo Loach is a peaceful, social species best kept with other cool-water fish. It will peacefully coexist with goldfish, hillstream loaches, and similar temperate species. It is a burrowing species that will disappear into soft substrates, so fine sand is essential. Its curious, interactive personality and weather-predicting reputation make it a uniquely entertaining aquarium inhabitant. The intestinal breathing adaptation of Misgurnus anguillicaudatus is particularly well-developed compared to other cobitid loaches, allowing it to absorb up to 30% of its oxygen requirement from gulped air. This makes it uniquely tolerant of hypoxic conditions and explains its widespread distribution across rice paddies, drainage ditches, and stagnant ponds where gill-breathing fish could not survive.
