Imperial tetra

This ornamental fish is native to the west coast of Colombia. There it lives in Río San Juan and its tributaries. It can live up to 9 years in captivity with good care. The fish are suitable for beginners.

What makes Kaisertetras stand out?

Sitron, Nematobrycon palmeri, CC BY-SA 3.0

The following attributes apply to the Emperor Tetra without restrictions: It looks beautiful, is peaceful, remains small, is light, easy to feed, does not eat aquatic plants and is easy to maintain. In short, an ideal aquarium fish. It feels most comfortable in a shoal of at least 10-12 animals. The emperor tetra is a peaceful but lively fish. The males like to jump out of the aquarium, therefore a cover is necessary. Kaisertetras can be socialized with other peaceful especially bottom fish (e.g. Corydoras catfish).

There can be problems with roommates in the upper water layers, because the males of the Kaisertetras are territorial and defend their territory, especially during spawning time. A single male can then possibly dominate the whole aquarium. Other fish have to push their way into the corners and are attacked as soon as they leave them. However, this behaviour can be avoided with appropriately large aquariums.


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The appearance of Kaisertetras

The fish have a conspicuous flag-like dorsal fin, which is decorated by a fine black stripe. The fish body is of a shimmering blue coloration on both flanks. Below the lateral lines there is a black longitudinal band extending from the rear edge of the gill cover to the root of the tail. The colouring of the belly and caudal fins is slightly yellowish to bright yellow.

Sex differences

The emperor tetra reaches a maximum length of about 5 cm. The male fish are slightly larger than the female and also have a larger dorsal and anal fin. The iris of the males glows blue, that of the females green. During the mating season the belly of the males glows purple and the fins have a contrasting pattern.

Water values for Kaisertetras

  • PH value: by 5.5-7.5
  • Water hardness: 5°-15° dGH
  • Temperature: 23°-27° C

Feed and nutrition for Kaisertetras

The imperial tetra is omnivorous. The fish eat a lot. The feeding should therefore be done with a balanced mixture of live, flake or frozen food, Artemia, insects, mosquito larvae but also vegetable food.

The ideal aquarium for Kaisertetras

The aquarium should have a minimum capacity of 112 L. The fish like to stay in the upper and middle basin area. The tank should also not be too bright (it is best to cover the water surface with floating plants) and have dense border planting. With too much light the fish will become pale. The substrate can be dark foliage or peat.

Keeping conditions

The fish with their unusual fin shape show their best colouring in darkened tanks. With their conspecifics they swim around in a loose formation or even alone in the aquarium under optimal keeping conditions and thrive magnificently. In the following the most important keeping conditions in short form:

  • Company tank
  • Plants and free swimming space
  • as roommate preferably bottom fish
  • Schooling fish
  • Group housing from 10 animals
  • Omnivores

Special features of Kaisertetras

The longitudinal iridescent blue longitudinal stripe is more pronounced when the fish is well. It then glows much more intensely.

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