Fish within the Cyprinidae family make excellent aquarium subjects for three main reasons. First, there are over 1,500 species to choose from; second, they are very adaptable; and, third, they range in size from around 1 in up to 1 ft, meaning that there is a family member to suit any fishkeeper. Unlike some other fish species, cyprinids do not have teeth in their mouths, but this is balanced by the presence of pharyngeal teeth in the throat, which help grind up food as it passes to the stomach. Close examination of the arrangement of these teeth enables ichthyologists to identify, or distinguish between, various species.
Within aquarium circles, three main tropical groups stand out in the family -- barbs, danios and rasboras. While cyprinids are members of the Cyprinidae family, this family is one of the larger order of Cypriniformes. Another family within this order is the Cobitidae family. This popular group of fish is commonly known as loaches.
The popularity of cyprinids is not limited to tropical species. The family also boasts several genera that are classed as coldwater fish, which means that those fish do not require heated aquarium water. The favorite among coldwater cyprinids is, of course, the goldfish, Carassius auratus, together with its many varieties. Cyprinids are called "opportunistic spawners" - ripe adults come together to spawn using egg-scattering methods and for the most part do not exercise any parental care, although the spawning method of Rasbora heteromorpha differs from the norm as it deposits its eggs beneath plant leaves.
Cyprinids are generally easy to keep, being hardy, resistant to diseases, and very accomodating in their housing and feeding needs. Apart from a varied diet, all they require is a clean, suitably furnished aquarium (usually with plants), although some species do have vegetarian tendencies. For breeding, it is normal practice to use a separate breeding aquarium, set up with spawn-saving precautions, as cyprinids have a taste for their own eggs.