Animal-World > Freshwater Fish > Characins > Cardinal Tetra

Cardinal Tetra

Family: Characidae

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Paracheirodon axelrodi Photo © Animal-World: Courtesy David Brough

   The startling coloration of the Cardinal Tetra is all natural, and arguably unsurpassed in freshwater fish!

   The Cardinal Tetra is the most popular aquarium fish (sales wise) of all time and is very charming in appearance and behavior. A serene yet gregarious fish, it is known as the Neon Tetra’s “big brother”. The two are very similar however the Cardinal Tetra is slightly more delicate. In addition, the red coloration of the Cardinal Tetra extends through its whole body length.

   The Cardinal Tetra will only be comfortable in a school. Buy the best stock available to you, preferably from a local breeder as opposed to a mass produced type. Also choose its tank mates well, as it is the natural prey of many fish, even many of the other tetras. With optimal water conditions and a well thought out tank, the colors will become even more radiant. Keep its water soft and acid. Plant the tank heavily, providing some hiding places and a lot of swimming space. Dark substrate and bogwood will make this fish's coloring even brighter. They also do not like harsh light, nor will it help its coloration.

   If it is kept in good conditions, the Cardinal Tetra is easy to keep and will resist disease. However, if the tank is unstable, it will die off very quickly. The worst fear of a tetra keeper is the Neon Tetra disease, an essentially incurable and highly contagious disease of unknown origin and cause. See the Neon Tetra bio for more info.

For more Information on keeping this fish see:
Guide to a Happy, Healthy Freshwater Aquarium

Distribution:
   The Cardinal Tetra was described by Schultz in 1956. They are from slow moving creeks in South America, notably the Rio Negro and Orinoco where they live in shoals, mainly in the middle water layers and feed on worms and small crustaceans. Many individuals are wild caught for the aquarium trade, making it necessary to recreate their natural lifestyle in captivity.

Status:
   The species is not listed on the IUCN Red List.

Description:
   The Cardinal Tetra is a very small tetra species. They have a bluish body with an electric blue neon stripe running vertically from the nose along the length of the body. It is underscored with a very beautiful broad red stripe from the head on back. It is similar in appearance to the Neon Tetra, but the red stripe on the Neon runs only halfway up the body.

Size - Weight:
   These fish will rarely exceed 2 inches in length (5 cm).

Photo © Animal-World

Care and feeding:
   Since they are omnivorous the Cardinal Tetra will eat most appropriately sized foods. It has high vitamin requirements, so at least 75% of its food should be quality flake food. Cardinal tetras especially appreciate live foods, but if fed them exclusively it may reject prepared food later on.
   Keep its tank very clean, as it will not tolerate poor water. The Cardinal Tetra is a blackwater fish, so the aquarium should be dimly illuminated and the water needs to be very soft. Hard water can be problematic, building up calcium salts in their kidney tubulli.

Water Region: Top, Middle, Bottom:
   These fish will swim anywhere, but favors the middle of the aquarium or wherever the most swimming space is. It will spend a lot of time in the shadows, mimicking its natural behavior.

Acceptable Water Conditions:
   Temp: 73 - 81° F (23 - 27° C), (75° F (24° C) for breeding)
   Hardness: 2 - 8° dGH (1.0 - 2.0° for breeding)
   Ph: 4.5 to 7.0 (5.0 - 6. for breeding)

Social Behaviors:
   The Cardinal Tetras are good schooling community fish that will get along with everyone. The bigger the school, the better its coloration becomes. Keep in mind that it will be eaten by most any fish that can, so choose its tank mates well. It is the natural prey of many fish, even many of the other tetras.

Sexual Differences:
   It is difficult to spot, but males are generally more slender with a hook protruding from the anal fin.

Breeding/Reproduction:
   Breeding the Cardinal Tetra is very tricky in home aquariums. Water conditions must be optimal, and pairs compatible. They will need subdued lighting, as will the fry. They will spawn in the evening, laying up to 500 eggs. Eggs will be scattered, and parents will eat them if not removed. Fry are very tiny and delicate, therefore very difficult to care for.

Buy Cardinal Tetras From LiveAquaria.com

   See a general description of how to breed these fish in Breeding Freshwater Fish and Fish Food for Fry for more information.

Availability:
   The Cardinal Tetra is available almost everywhere, in stores and in online catalogs, however many shops choose to stock the more reliable Neon Tetra.

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Latest Comments
I bought 6 of these fish for my 30 gallon tank over a year ago now. By no means an 'expert' fish keeper at the time i didn't expect to have much luck with them (Especially as they were very very small at the time of purchase). The store owner recommended many 'Cardinal water products' that i declined and i took these fish home and hoped for the best. A year later i have 5 healthy and quite large Cardinal tetra's (i lost 1 within a few days of purchse). These fish really are beautiful and peaceful. They live happily with my Lemon and Flame tetra and a recently purchased pair of dwarf gourami. The flame tetra often show courting and mating behaviour which seemed to 'excite' the cardinals into courtship and mating behavour themselves. Although i don't intend to breed them - for those who do they seemed most willing to mate whilst they were younger. All in all i havn't found them anymore difficult to keep than any other fish and have avoided the use of expensive 'Cardinal specific products'. Kate 2006-06-08
Comments Dr Jungle REALLY Likes to Hear!
I have a shoal of only 5 guys in my 110 liter tank with 3 amazon algae eaters. I am restocking my fish tank soon but until then these guys are being the most perfect fish you can get! I love this site by the way. Kurt van Wyk 2009-02-27
Cardinal Tetra... As suggested, it is one of the most popular fishes in the world. I bought about 80 fishes for my 3 and 1/2 feet tank. All the fishes were great and displayed shows of blue and red colorizations. Needless to say, it is my favorite charachin of all time next to the neon of course. Still, i would recommend all aquarists to buy this fish, but it will be at its best when the substrate is dark and soft and acidic waters. It does better in a heavily planted, well-balanced aquarium. By the way, Great Site!!! Yee Loon 2007-07-05

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Author: Yvonne
Additional Information: Clarice Brough, CFS.