One of the most enjoyable species in any community tank is the corydoras catfish. These oddly shaped little fish, one to three inches long, resemble tiny sturgeon with humped backs, armor-plated flanks, flat bellies, and distinctive whiskers called barbels on the sides of their downturned mouths.

Native to South American streams and rivers, these little catfish are devoted bottom dwellers that seem to be in constant motion, wriggling along the surface of the sand or gravel looking for food.

More than a hundred species have been identified and some two dozen of the most colorful are readily available in aquarium shops. They may be called corys, mailed or armored catfish, or just corydoras cats. Some of the most popular are dwarf – or pygmy – catfish, leopard, peppered, bronze or skunk corydoras. There is also a marvelous pinkish white albino corydoras.

Good for Community Tanks

They are freshwater fish that do well in schools and different varieties will swim together. What makes them such a good choice for the community tank is that they are small and seem to ignore any other fish, preferring to pursue their incessant study of the bottom. They are also hardy fish that accept temperatures in the 70s Fahrenheit, neutral water conditions, and any food that will float to the bottom. While they may help clean up food the other fish miss in feeding, they can't live on scavenging alone. Find food that will reach the bottom for them – best of all, sinking pellets made especially for catfish.

While some of these species, the peppered corydoras, for example, will breed in a tank set up for them, you may not know what to do with your hatchlings since the adults will live anywhere from five to 10 years.