Loaches are freshwater fish belonging to the family Cobitoidea. They are among the most diverse group of fish, with 1249 known species. They are natives of Northern Africa and Eurasia, where they are found in creeks and rivers. Being hardy fish, they are easy to keep in aquariums.
Given their diversity in species, loaches have many different shapes, colors, and sizes. The smallest loach breed is the dwarf chain loach which grows to about 2-2.5 inches (5-6 cm). The largest loach breed is the imperial flower loach which can grow to 1.6 feet (50 cm).
They are also highly adaptable with species found in high and low altitude areas and even blind ones in dark caves. They prefer temperatures of 59-77°F (15-25°C). They thus don’t need a heater when in an aquarium.
Loaches are bottom-dwellers and will thus spend most of their time at the bottom of the aquarium. They are schooling fish with the schools having a leader. They are also aggressive and can attack the rest of the fish in a tank.
Most breeds of loaches closely resemble eels but can be quite diverse since some have broad, ray-like bodies. They can also be used as food since most Asian cultures eat them.