European Weatherfish

Misgurnus fossilis, the European Weatherfish, is the largest member of the genus and one of the most distinctive freshwater fish native to Europe. Found from France east to the Ural Mountains, it inhabits slow-moving rivers, oxbow lakes, and swampy ponds with soft, muddy bottoms. Reaching up to 35 cm, it is considerably larger than the Asian dojo loach and demands a spacious aquarium.

The European Weatherfish earns its common name through the same mechanism as M. anguillicaudatus: barometric pressure sensitivity causes hyperactive behaviour before storms. It is also a facultative air-breather, surfacing periodically to gulp atmospheric air, which is processed in a specialised intestinal blood supply. This adaptation allows it to survive in poorly oxygenated swampy habitats.

Aquarium care requires cool water, very deep fine substrate (at least 8–10 cm), and excellent filtration to handle the significant waste production of this large loach. Feeding is easy: it accepts most sinking foods eagerly, including pellets, earthworm, frozen bloodworm, and blanched vegetables. The European Weatherfish is a long-lived, fascinating species best suited to a large coolwater or pond-style aquarium.

Water: pH 6.5–8.0, temperature 5–20°C; tolerant but prefers cool, oxygen-rich water. Tank: 200 L minimum; very deep fine sand (8–10 cm), robust décor, strong filtration, tight lid. Feeding: Sinking pellets, earthworm, frozen bloodworm, blanched vegetables; large appetite. Breeding: Spring spawner; requires pond conditions with temperature variation to trigger. Compatibility: May eat very small fish; best with robust temperate cyprinids of similar size.