Weatherfish

Identification

The weatherfish is an elongated, eel-shaped fish reaching 15 to 30 cm. The body is laterally compressed with ten barbels around the mouth (five pairs) — more than any other Dutch fish. Color is brown to ochre with dark longitudinal stripes along the flanks. The belly is light orange-yellow.

Behavior & ecology

The weatherfish is known as a living barometer: when atmospheric pressure drops, it becomes restless, rises to the surface, and gulps air — a form of intestinal respiration that also allows survival in oxygen-poor water. This behavior was traditionally used to predict weather. The species lives buried in soft, muddy bottoms of ditches, ponds, and floodplains. When water dries up, it burrows deep into the mud and can survive for months.

In the Netherlands

Protected under the EU Habitats Directive (Annex II) and Dutch nature conservation law. With 1,600 records in our database, it is the best-documented protected fish species. Found in peatland areas, river clay landscapes, and polder ditches, especially in Overijssel, Friesland, Noord-Holland, and the river district. Dredging, bank reinforcement, and intensive ditch maintenance are the main threats.