Breeding betta pugnax – the mouthbrooding betta

Betta pugnax breeding (mouthbrooding betta)

What you will need

  • male betta pugnax
    male betta pugnax green scales on sides and gill covers

    36 inch aquarium, hood and lights

  • tank divider
  • 200w heater – stat
  • 1 male and 1 female
  • many bushy plants and floating plants
  • java fern java moss
  • plant pot shelters
  • hiding places
  • high flow internal power filter
  • sandy substrate

Betta Pugnax: General care

Betta pugnax can be kept and bred in a community or a species aquarium. Males can be recognised by the stronger colours and longer fins. At nearly 4 inches they are bigger than betta splendens. Water must have a flow such as that from an internal power filter. Because they grow in rivers betta pugnax does not build a bubble nest that would be swept away. Instead they have evolved to mouth brood the eggs and new born fry. The male does the mouthbrooding. The male’s head is also larger to accommodate a large brood. A water temperature around 77F is generally ideal for them. Slightly acidic water that is quite soft, about 10dh or less. Remember, being an anabantoid a tight fitting lid is essential, especially for the new born fry if the room temperature is cold compared to the aquarium temperature.

Betta Pugnax: Preparation for breeding

Raise the temperature to 82F. Feed well with live food (including mosquito larvae) several times a day. They can be left in the community tank to breed.

Betta Pugnax: Breeding

female betta pugnax
female betta pugnax 3 horizontal bands and paler colour

Mating has some similarities with nest building bettas. However, the female is the more active. The male darkens and becomes greener and the female lightens showing her 3 dark bands. The male’s embrace seems less tight than betta splendens and the male does not turn the female over. Eggs are released during the embrace and fertilised. They land on the males anal fin. The female quickly recovers and gathers the eggs from the male’s anal fin. She then spits the eggs out and the male catches them into his mouth. Then the embrace starts again and the process repeats until the female has laid all her eggs. There may be up to 100 eggs but usually less around 40 is normal.



If the male eats the eggs or spits them out then you may consider just having the male and female pugnax in the aquarium with no other fish. If it was the first time they bred or it was caused by some stress then you may want to persist in the same aquarium.

Raising the Betta Pugnax young

male betta mouth brooding
male betta pugnax mouth brooding  with enlarged throat area

When mating has finished put a tank divider to section off the male. Any other fish inside the male’s section can be gently caught and removed to the rest of the tank, including the female. Make sure that the male is not disturbed during this process. Males are very prone to eat their own brood.
After 4 days they hatch in the male’s mouth. After another 4 days they become free swimming and are released from the male’s mouth. He takes no further care of the fry. Remove the male after he has released all the fry.
Feed the young fry on brine shrimp, sifted daphnia and microworms. Do frequent small water changes with aged water.

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