The rasbora is a genus of small minnow-type fish in the Cyprindae family. Many times fish from similar genera, such as Microrasbora, Trigonostigma and Boraras are generically referred to as rasboras as well. Various species of rasbora are popular aquarium fish because they are small, brightly colored and peaceful.
While rasboras share the same genus as carps, they have more in common with danios, another genus of small, brightly colored fish popular with aquarium owners. Most species of rasbora are found in Southeast Asia in countries such as Sumatra and Thailand, however some species are native fish of Africa. Almost all of them are very small, usually only growing to about 2 inches (5 cm) in length.
For aquarium enthusiasts, one of the most popular species of the fish is the harelquin rasbora. This fish stands out because of its unusual coloration; its bodies are almost split down the middle into black and white halves. The front half is white, while the backside is black with a small streak of red extending to the tail fin.
These fish are best suited for groups, and do well in schools of six or more. It is a hardy species that is good for beginners, as it can survive a variety of water conditions. Harelequins can thrive in waters that range in temperatures from 73 to 82 degrees Fahrenheit (22 to 27 Celsius), and with a pH level between 5 to 7. Since they should be kept in schools, a tank that is at least 20 gallons (75 liters) in size is preferable.
Another popular species of the family of fish for aquarium owners is the scissortail rasbora. Scissortails are thinner and narrower than harelquins, and can grow a bit larger, usually to 6 inches (15 cm) in length. It is usually black, gold or silver in color, and its most notable characteristic its tail from which it gets its name. It too is a peaceful fish, but its water conditions must be slightly more strict. It prefers a pH level between 6 and 6.5 and a water temperature between 73 and 77 degrees (22 to 25 Celsius). It must be kept in schools, usually in numbers of four or higher. It also has the reputation of being a jumping fish, so the aquarium should be covered at all times for its own safety.
There are many other species of rasbora that are commonly found in aquariums around the world. These include the red dwarf, emerald eye, axelrod and vaterfloris rasbora. With rare exception they are all peaceful fish that are suitable for nearly all aquarium owners.