A loach is a type of freshwater fish belonging to the family Cobitidae. These small, elongated fish are commonly found in rivers and ponds across Asia and Europe. Loaches are known for their unique appearance, often featuring a slim body and barbels around their mouths, which help them search for food in the substrate. Loaches are popular in the aquarium trade due to their interesting behaviors and peaceful nature. They typically feed on small invertebrates, algae, and detritus. Some species, like the weather loach, are also known for their ability to sense changes in weather, making them fascinating pets for fish enthusiasts.