Misgurnus fossilis; Print; Misgurnus fossilis is a species of loach in the genus Misgurnus. It is commonly known as European weatherfish or European weather loach; due to its activity patterns changing when air pressure rises or falls. If there is a sudden change in barometric pressure; the weatherfish comes to the surface and swims about excitedly. In water with a low oxygen content it gulps air; it extracts oxygen through its intestinal mucous membrane; which has a complex system of blood vessels. It feeds on thawed frozen blood worms; small fish; brine shrimp; earthworms and some vegetables. It is quite an active loach and can grow to a length of 30 cm.; 1700-1880