Scientific Name : Paracheirodon axelrodi
Common Names : Cardinal Tetra
Care Level : Easy, acclimate slowly to your tank water and don't even think about adding them to an aquarium that has not completed the aquarium nitrogen cycle.
Size : Up to 2 inches (5 cm)
pH : 5.5 - 7, prefer water slightly on the acidic side
Temperature : 73°F - 80°F (23°C - 27°C)
Water Hardness : 2° to 6° dH
Lifespan : 2 - 5 years
Origin / Habitat :
Temperament / Behavior : This is a very peaceful tropical fish and best kept in schools of 6 or more.
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).
Cardinal Tetra setup:
When you set up an aquarium for Cardinal tetras it is always a good idea to include a lot of plants. An open area for swimming is also recommended. Floating plants that dim the light a bit will make your Cardinal tetras spend more time out in the open. Cardinal tetras should always be kept in groups consisting of at least five Cardinal tetras. Larger shoals are recommended, so if you have place for 10 Cardinal tetras or more you should definitely go for the higher number. Keeping only a few Cardinal tetras will result in shy and stressed fish. Cardinal tetras are non-aggressive and commonly kept in community aquariums with other peaceful tropical fish species of similar size. The Cardinal tetra is a good choice if you are looking for fish that will occupy the top and mid part of the aquarium.
The recommended minimum aquarium size for cardinal tetras is 60 centimetres (24 inches). Cardinal tetras are more sensitive to poor water conditions than the Neon tetras, and it is always easier to maintain a high and stable water quality in a large aquarium than in a small one. Getting an aquarium that is large enough is especially important for beginner aquarists that wish to keep Cardinal tetras. If you are a skilled aquarists that knows how to maintain perfect water conditions, it is however possible to keep Cardinal tetras in aquariums no larger than 20 litres (5 gallons).
When it comes to water chemistry, you should try to make the conditions in the aquarium similar to Rio Orinoco and
Rio Negro. These South American rivers are renowned for their extremely soft and acidic water. The pH in the aquarium should therefore ideally be kept between 4.0 and 6.0. It is possible to gradually adapt Cardinal tetras to harder conditions and even alkaline water, but living in such an aquarium will make the Cardinal tetra more sensitive and less resilient towards illness. The water temperature should between in the 23 – 27° C (73.5 – 80.5° F) range. You can adapt the Cardinal tetra to a slightly higher temperature without weakening it if you allow the transition to be slow and gradual.
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.
Cardinal tetras have been successfully bred in captivity, but breeding them is quite difficult and a majority of the Cardinal tetras sold in pet shops are therefore wild caught from Rio Orinoco and
If you want to try breeding Cardinal tetras you must provide them with ideal water conditions. Switch from flake food to plenty of live food and include fine leaved plants in the aquarium set up. The Cardinal tetra is a non-guarding open water/substratum egg scatterer that will prefer to deposit the eggs among plants. Over 500 eggs can be released in one spawning. The eggs will hatch after 24-30 hours and it will then take an additional 3-4 days before the fry are free-swimming. Really small fry-food is necessary since the miniscule Cardinal tetra fry can not handle large food types.
The fry are very sensitive to poor water conditions and you can expect very high death rates if you do not keep the water quality at supreme levels. Another threat is the adult fish. Since Cardinal tetras are non-guarders, they will not hesitate to eat eggs and fry. If you want to breed Cardinal tetras it can therefore be a good idea to set up a separate fry rearing aquarium.