Tetras are a small species of fish originating from streams and rivers throughout the tropical and subtropical zones of south and central America, as well as Africa. They are members of the Characidae family, which are distinguished from other species by a small adipose fin situated between the caudal and dorsal fin.
IN THE AQUARIUM
Most tetras are suited to peaceful community tanks, as they have a peaceful, non-aggressive temperament. They are active schooling fish and do better in groups of ten or more of the same species – more always being the better choice.
In their natural habitat, they live in soft acidic waters with temperature ranging between 25° to 28° C. Like with most species, the males will establish a home territory which they will defend. This adds to a liveliness in the tank, rather than aggression. Tetras do best in well planted aquariums with moderate lighting and dark substrates, which display their vibrant colours best. Species such as the cardinal tetras count among the most popular of tropical aquariums and add a wonderful touch of vibrancy and social interaction actions to the community tank.
Suitable tank mates for the smaller tetras include rasboras, dwarf cyclids,corydoras, hatchetfish, pencilfish and plecos.Larger tetras such as Bleeding Heart, Diamond and Congo tetras can be kept with larger fish such as Angelfish and Discus.
Breeding Tetras in your tank can be a hit and miss affair, because most aquarists either do not have them in large enough groups, or do not have enough time to pay attention to small detail. If you would like to breed with tetras, read an excellent, detailed article on the process here.