Pond Loach

• It becomes agitated and swims in circles when the air pressure drops before a storm, behaviour that earned it the name of weather loach and that was used for centuries as a household barometer in Japan.
• It breathes through its gut: it gulps air at the surface, absorbs the oxygen through the intestinal wall and expels the rest through the anus.
• It can survive buried in the mud for weeks if the pool dries out.
• It breathes air through its intestine, just like the bronze cory, which lets it hold out in almost oxygen-free water and survive buried in the mud when the water disappears.
• It is known as the weather loach because it grows restless when atmospheric pressure falls before a storm: it is sensitive to barometric changes.
• It has been introduced into Europe, North America and Australia, and in several of those places it is listed as invasive.
• It is farmed and eaten in Japan, Korea and China, where it is a traditional freshwater food fish.

Skeleton type

Vertebrate - internal bony skeleton (fish)

Habitat & environment

Soft bottoms of rice paddies, canals, ponds and slow-flowing rivers

Sources consulted: FishBase (Froese & Pauly, eds.); Lista Roja de la UICN; Nico y Fuller, USGS