Tropical Fish: Tetras

Cardina Tetra

Paracheirodon axelrodi

The cardinal tetra is probably the world's favorite tropical fish in terms of numbers kept. I doubt if there is a hobbyist in the world who has not, at some point in time, kept cardinal tetras. And, while they have been bred, they have never been bred in commercial quantities.

Millions of cardinals are caught wild and exported from Brazil every year. Dr. Labbish Chao has started a program called Project Piaba (piaba is the native name for little fish that swim with cardinals) to help educate collectors/exporters and improve the conditions under which the fish from Brazil are caught, conditioned and shipped to the world.

Even though millions are caught every year, the fishery is managed very well. The fish are not allowed to be caught during the breeding season or shortly thereafter, and the Amazon/Rio Negro area is so vast that fishermen do not go back to the same site for years, thus allowing the cardinals to replenish.

Keeping cardinals in the home aquarium is very easy as long as two conditions are met. First, do not keep them with larger fish (such as angelfish or other large cichlids) that quite naturally look upon cardinals as food. And second, they really do need soft, acid water. If your water does not meet these parameters you can try to adjust it by using reverse osmosis or deionizer water, or putting a peat pillow into the filter. Once the pH starts getting above 6.8 and/or the hardness above 12 DH, cardinals don't do well.

When given the water conditions they like and kept in a tank without any predators, cardinals will do spectacularly well. They will eat absolutely any food: flake, frozen, freeze-dried or live. They do not bother their tankmates. Like all schooling fish, cardinals are best kept in groups of at least six or eight, and more if possible.

Source: aquarium fish magazine

Compatibility: Tetras, Rasboras, Danios, Dwarf Gouramis, Discus, Angelfish, Rainbowfish, Livebearers, Plecos, and small Scavenger Catfish.

Tetra Care:

Most species will adapt to a range of water conditions so long as the water is clean and well aerated. Extremely high pH (e.g. over 7.6, or 8 for hardy species) and very hard water should be avoided.

Most tetras will fade in color if they are stressed or uncomfortable with their surroundings. (But note that many lose all their color at night, which is not a cause for alarm).

They are schooling fish and will not be happy unless kept in a group of at least four of their own species.

Large fish such as Gouramis, Angelfish and Silver dollars should be avoided: even quite passive fish will eat other fish if they can fit them in their mouths!

Larger tetra species such as buenos aires tetras, congo tetras, serpaes and others can be mixed with quite large tank mates.

Tetra Related Articles:

The Bleeding Heart Tetra: is a hardy, peaceful, schooling species that should be kept in groups of six or more. It does extremely well when kept with other peaceful fishes, such as Megalamphodus, Corydoras and Nannostomus species.

The Neon Tetra was the first wild-caught fish that really set the tropical fish hobby into a dither, and contributed much to establishing the "tropical" fish hobby.

Breeding Tetras Tetras are egg scatterers that do not tend their eggs or fry and so a separate spawning/fry tank is needed. Spawning occurs usually between pairs, although some species spawn in schools.