Redtail Rasbora (Rasbora borapetensis)

Redtail Rasbora Rasbora borapetensis
Name	Redtail Rasbora
Name Lat.	Rasbora borapetensis
Family	Danios
Family lat.	Danionidae
Order	Carps
Order lat.	Cypriniformes
Origin	Southeast Asia
Habitat	Streams, ponds
Diet	Carnivore
pH	6.0-7.5
Behavior	Peaceful
Keeping	Group, school
Care Level	Moderate
Reproduction	Egg scatterer
Breeding	Difficult
Life Span	3-5 years
Protection	No
Metric Units
Size	5 cm
Temperature	22-26 °C
Hardness	2-12 °dH
Aquarium	~ 120 l
US Units
Size	2"
Temperature	72-79 °F
Hardness	36-214 ppm
Aquarium	~ 30 gal

Distribution and habitat

Red-tailed Rasbora are common in the tributaries of the Mekong and Chao Phraya rivers and in the inlets of the Mae Klong in western Thailand. They live in slow-flowing or stagnant waters, where they usually stay in shoals in places with dense vegetation near the banks.

Maintenance

The aquarium should have a dense border planting, with hiding and retreat possibilities (roots, stones) and offer sufficient swimming space. In soft, slightly acidic water, subdued light (floating plants) and a dark substrate covered with some foliage (e.g. sea almond leaves) they show the most beautiful coloration.

No ammonia, ammonium and nitrite should be detectable, the nitrate value should not exceed 100 mg/l. To ensure the water quality and oxygen content, a filter and heater adapted to the aquarium size is required, as well as lighting for the species-appropriate day-night rhythm of the animals.

Diet

In nature they feed mainly on insects and insect larvae. The food supply consists of live, frozen and dry food. For a balanced diet, feed once a day with a high-quality, protein-rich dry food (flakes, granules, pellets) as well as cyclops, moina, daphnia, artemia, mosquito larvae, etc. (live or frozen)

It is recommended to feed small portions several times a day. Only feed as much as will be eaten within a few minutes. A regular and varied diet promotes health and prevents deficiency symptoms.

Behaviour and compatibility

They are lively and very peaceful schooling fish, well suited for a community tank with other small and peaceful fish. A group of at least 8 animals should always be kept together, but preferably more. In a too small group they remain shy and colorless.

Basically, only compatible fish species with similar demands on water condition and water temperature should be socialized.

Sex dimorphism

The sexes are difficult to distinguish outside the spawning season. The males are much slimmer than the females.

Reproduction and breeding

They are free spawners. The female spawns between fine plants (Java moss) near the bottom. The larvae hatch after 24-48 hours and swim freely after about 3 days. The parents do not perform brood care and should be separated from the fry after spawning, as they are spawn predators.

Fry must be fed several times a day with special rearing food (Artemia nauplii, microworms, dust food). In a community tank breeding is hardly possible, because the spawn is easy prey.

Important

The aquarium should be well covered, because they like to jump.

The foliage (sea almond tree, oak, etc.) enriches the water with humic substances and naturally lowers the pH

The well-being of the fish should be checked regularly. Temperature should be checked daily, pH, hardness and nitrate levels should be checked at least every 14 days. Regular partial water changes are recommended, even if the contaminant level has not yet reached the upper limit. Sudden changes in water quality should be avoided. Newly introduced fish must be accustomed slowly to the water in the aquarium.

Further literature can be found in your pet store.

References

Text: Sylvia Hos; Image: Franz Lowak

Source: BMELV (1998): Tierschutzgutachten - Haltung von Zierfischen (Süßwasser); RIEHL & BAENSCH (2006): Aquarien Atlas Bd. 1, Mergus Verlag; ENGELMANN (2005): Zootierhaltung - Tiere in menschlicher Obhut: Fische, Verlag Harri Deutsch

• Gemäß § 21 Abs. 5 Tierschutzgesetz idgF