Breeding rasboras

Breeding rasboras

What you will need

  • rasboras breeding pair male on left
    Male and female breeding pair of harlequin rasboras

    2 foot breeding tank with hood and low lighting

  • floating plants to provide shade
  • several broad leaved plants such as amazon sword
  • several bunches of fine leaved plants dotted about the aquarium
  • 150w heater stat
  • sponge filter with air pump

General care and information

They are the perfect community fish. Many species are easy to breed. Most species will take just dried food. Males are more colourful and females are more plump.

Temperature should be kept at 76F. The water should be at 10dh hardness and a ph of 6.5. Some of the more difficult to breed rasboras, such as the harlequin rasbora, will need reverse osmosis water to obtain the required softness needed to breed them.

Some of the species have light sensitive eggs that will die if exposed to much light. This includes hengels harlequins, harlequins, dwarf rasboras, ocellate dwarf rasboras and some others. Check to see if your breed of rasbora has light sensitive eggs. Cover most of the surface with floating plants so that the aquarium is quite dim.

Preparation for breeding

harlequin pair spawning
harlequin pair spawning under broad leaved plant

Although popular, harlequins are difficult to breed. So it might be a good idea to practice with other rasboras first.

They need very soft water of 2dh and a ph of 5.5 and a temperature of 82F. For other rasboras use the above parameters. Dark substrate will help. The use of peat in the filter or in a nylon sock will help too.

For other rasboras raise the temperature to 80F.

Feed well with live food at least 3 times a day. Do 5% daily water changes with aged water. Darken the lighting if the aquarium is too bright.



breeding group galaxy rasboras
breeding group of galaxy rasboras diving into plants

The males chase the females around the aquarium. Most species spawn amongst the plants. The females will swim through or over the plants laying eggs with the male fertilising the eggs. Harlequins actually breed upside down and lay eggs on the underside of a broad leaved plant such as an amazon sword. When the females lay their eggs the males will entwine themselves with the female. The male will embrace the female by placing his tail over her tail when he fertilises the eggs.

Raising the young

Remove the adults from the aquarium. Cover the sides, front and back with paper to block out the light.

Add some methylene blue to the aquarium because the eggs and the fry are susceptible to infections.
After 1 to 2 days the eggs hatch.
After a further 3-4 days the fry become free swimming. They must be fed with an unpolluted source of infusoria at least 4 times a day. After 1 week start feeding with brine shrimp and daphnia.
Do a 10% water change every 2 days and top up the methylene blue at night after all feeding has finished. Be careful with the water changes use aged water with exactly the same parameters as the aquarium.  The fry grow quickly.

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