Loaches are freshwater fish of the family Cobitidae, small benthic (bottom-dwelling) fish with a flattened ventral profile. There are 160 different species of them. Loaches are mostly scavengers and are omnivorous, usually not very picky about their food. They may eat aquatic crustaceans, insects and other small invertebrates as well as scraps of organic detritus. Many live in waters of generally poor quality and feed on tubifex worms which are associated with those areas. Some have adapted to less-than-ideal water conditions by being able to gulp up atmospheric oxygen from the air. Loach species are distributed through Europe, Asia, and in Morocco. They mainly inhabit rapid-moving streams.
Because of their scavenging nature and their ability to adapt to many freshwater ecosystems, some loaches have been introduced to waters in regions which they are not native to and may pose problems to local wildlife as an invasive species.
The body forms of various loaches range from being vermiform (worm-shaped; long and thin) to Fusiform (spindle-shaped; cylindrical and tapering toward the ends). Most loaches do not have true scales. Like catfishes, loaches have the sensory organs known as barbels; usually 3-6 pairs of them. Some other characteristics of loaches are a small bottom-facing mouth suited to their scavenging benthic lifestyle, an erectile spine below the eye, and a single row of pharyngeal (throat) teeth.
Loaches are active bottom dwelling scavengers ideally suited for the community aquarium. Loach fish consist of some of the most popular of all tropical fish, adding color, interest, and beauty to any larger community aquarium. Loaches are semi-aggressive fish when housed in the aquarium individually, so it is important to maintain each species in groups of six or more to minimize aggression.
The single most important feature you can provide in a tank housing loaches is the availability of hiding places. These can be driftwood, caves, bog roots or even dense thickets of plants. Loaches are shy in nature and need these places to feel secure and without them tend to jumpy and reclusive. Many of these families are nocturnal and will also use their refuges to rest during the day. Most of the Loaches will form territories around their hiding places and defend it from other members of their family. The next important feature of a tank housing these fish is the substrate or gravel, Due to their burrowing habit it should not be sharp or course sand or very fine gravel is best. In nature they feed on insect larvae and worms which they dig out of the substrate, some also graze Algae. In the aquarium they will do fine on flake or frozen food but remember due to their shyness you might want to feed them when the lights are out so the other fish don’t get all the food before they can get some.
