Weatherfish (Misgurnis fossilis)
Weatherfish are temperate, freshwater representatives of the largely tropical family of fish known as loaches (Cobitidae). The body is long and eel-like, and the mouth is surrounded by sensory barbells. The color varies depending upon location but is generally brown mottled with black, gray, and gold. The weatherfish grows to about 8 inches in length.
Many surprises await those who frequent live fish markets, especially ones serving Asian communities. Large loach species resembling weatherfish are often to be found there. These hardy creatures usually arrive alive and would likely make interesting aquarium subjects if they can be rehabilitated from the stress of capture and shipping.
A related Japanese species, which also inhabits temperate waters, is occasionally offered for sale. Many of the tropical species of loach are brightly colored and are popular aquarium fish. The weatherfish owes its common name to its unique habit of becoming very active during air pressure changes. This activity apparently results from the effects of barometric pressure upon the swim bladder, and medieval peasants in Europe were said to keep the fish for its weather predicting abilities.
Although they prefer to feed upon insects and small worms, weatherfish make excellent scavengers. They can tolerate a wide range of water temperatures. Most of their time is spent below the substrate with just the head exposed. As soon as food is scented by the barbels, the fish explodes from the substrate and swims wildly about, stopping occasionally to thrust the barbels into the gravel or sand. It is quite a hearty creature, and captive longevities of over twenty years have been reported. Weatherfish fare well on a varied diet consisting of black worms, crickets, flake food, and pelleted tropical fish foods.