Mouthbrooding Betta of Thailand

Story and pictures by Nonn Panitvong April 2002

Betta splendens, or Siamese Fighting Fish (Pla Kat), is one of the most popular fish in the aquarium world, originally from Thailand and South East Asia. In their homeland, the fish are very popular with people of all ages who raise them for both the pleasure of seeing them and for the fighting game. It sure not an overstatement to say that Pla Kat is a part of Thai culture. It is sad, however, that their mouthbrooding Betta cousins - which have very interesting behaviour - do not get as much attention as they deserve.

Generally we are all familiar with bubblenesting Betta, but this other group of Betta brood their eggs and young in the mouth. These species live in habitats where their water surface does not stay still - which would make bubblenest building impossible. There are currently 4 described, and 1 undescribed, species of mouthbrooding Betta in Thailand.

Betta pi                 Betta pugnax
Betta simplex      Betta prima
sp. "Southern Thailand"

Betta pi  TAN, 1998

This is the largest species of mouthbrooding Betta in Thailand. They can reach 12 cm.
Betta pi come from the swamp ('Pru' in Thai) area in the southern part of the country namely Pru Toe-daeng, the only area in the world that they can be found.

They live in tannin-stained water of a pH of around 5-6. Although they don't mind higher pH, I doubt if they will breed in such water. Tannin can be added to the water by mean of commercial "Black Water Extract" or you can use dry Oak leaves.

In Thailand, we use the dry Indian Oak leaves (Terminalia catappa ); if not available, dry Banana leaf will also do the trick. To be safe, I normally boil the leaves to extract the tannin.

I do not put the leaf in the tank directly. This also avoid the hassle of having to deal with the decaying leaf in the tank as well.

Another method that works well for me is to use a piece of driftwood in the tank. This can have Java Fern (Microsorum sp.) and Java Moss (Vesicularia sp.) attached to help absorb nitrate from the water and also act as cover for the fish. Alternatively, a flowerpot will also work well as a fish shelter.

The name Betta pi come from the fact that this fish have the pi (Pi is a Greek letter and the mathematical symbol for 3.124) mark on their chin. Being so big compared to other species of Pla Kat, this fish is called "Pla Kat Chang" by the natives - 'Chang' means Elephant in Thai!

The habitat of B. pi is constantly under pressure from the surrounding farming areas (rubber, oil palm) so for those who keep them, please try to breed them. I have not heard of captive breeding report of B. pi anywhere. You might be the first person!

Betta pi: This image shows the Pi mark under the chin of this species.

Betta pugnax (Cantor, 1850)

Betta pugnax is another large mouthbrooding Betta from Thailand. They can reach 7-8 cm.
B. pugnax can be found in highland streams in Southern Thailand all the way down to the island of Singapore.

The water in the streams is rather clear with almost neutral pH (7.1-7.5). The bed is reported to be gravel and the Betta can be found in the dense vegetation along the shore line where the water current is not so strong.

B. pugnax is one of the easiest mouthbrooding Betta to keep and breed. It is highly recommended to the beginner.

This is picture of a female B. pugnax. You can notice how she differ from the male in the first picture. You can separate male and female mouthbrooding Betta by the following points:

Female has smaller head structure
Female has smaller build overall
Female has less attractive color
Female has shorter fins

Betta simplex KOTTELAT, 1994

The only known habitat of B. simplex to date is the stream in the Krabi Province, southern part of Thailand.

They are medium size Pla Kat that will grow to about 5 cm.

The stream where B. simplex live has neutral pH and a mud floor that sometimes is covered with a carpet of Cryptocoryne crispatula.

In the picture, the male has a mouthful of eggs.

In mouthbrooding Betta, it is the male that hold the eggs in his mouth for 7-10 days before he releases the fry.

These huge fry, compared to those of the bubblenesting species, can normally take baby Brine Shrimp or Microworm right away.

The picture shows a 2 week old B. simplex fry taking refugee on a Java Fern leaf.

Betta prima KOTTELAT, 1994

B. prima
is a rather plain-looking mouthbrooding Betta.
They can reach the size of about 5 cm.

The known distribution area to date is in the central plain of Thailand eastward, to somewhere in Cambodia. They are found foraging among the dense vegetation along the banks of the stream where the pH is neutral with gravel bed.

They are easily bred and will shown their best colour - iridescent blue-green shine - in a dark tank with dense vegetation.

Like all other Pla Kat, B. prima will enjoy live food such as Mosquito larvae, Daphnia, Bloodworm, Tubifex worm and Brine Shrimp. If you use Brine Shrimp, make sure to rinse them well in freshwater as the salt is very bad for the kidneys of freshwater fish.

Betta sp. "Southern Thailand"

For an obvious reason, the exact habitat of this fish is being kept secret by those who found them. They are currently under the description process by Mr. Kottelat. The paper is due anytime soon, or it may have already been published, I'm not sure. Anyway, they are said to come from southern part of Thailand.

This fish looks very much like B. prima, but the main difference is in the mid-caudal fin ray: it is extended to form the ace shape, whilst the tail is rather more rounded in B. prima.

The picture shows a mouth brooding male.

In mouthbrooding Betta it is the female that initiates the spawning process.
She is the one who guards the surrounding area while the male - who does not eat anything during the brooding period - will keep a very low profile. He will look as though he has difficulty breathing all the time.

I normally remove the female once the spawning is done and I try to leave the male alone as much as possible. If you bother him too much he might eat the eggs!

This particular male spat out at least 7 fry on his 8th days of brooding.
Probably the first successful captive breeding report of his species in the world!

A male and female mouthbrooding pair, like this, will sometimes ‘dance’ side by side during the courtship.
The female with her fins all flared up will also dance around the male to get his attention. She will defend the breeding area.

This particular female had to put up with the nosy Betta bellica neighbour on the left.

This is a rather blue image of them copulating. The male is always the one on the bottom. His anal fin will act as a receiver of the eggs. After that the female will take the eggs into her mouth and spit them to him. The whole process can last several hours.

Reference: Goldstein, Robert J Ph.D.. 2001. Bettas A Complete Pet Owner's Manual, Barron's, New York
Special Thanks to:
K. Mee and Noung of Ta Pien Tong Fish Store, Seven Days Plaza; Mr. Anuratana Tejavej, Mr. Arthit Prasartkul and Pernille