Betta sp. Mahachai

Story and pictures by Nonn Panitvong April 2002

(with thanks to Robert J Goldstein for bringing this story to our attention)

One late afternoon in the October of 2001, I and my two good friends were standing on the shoulder of the highway in Mahachai area of Samutsakorn Province, Thailand.

In front of us was a swamp forest of the Nypa fruticans, a species of palm that only grows in brackish water areas. The water was very muddy. We didn't even know how deep it was. Being so close to the city and industrial area, we were not surprised by the presence of so much junk. There was everything from a small plastic bag to an old chair. I doubted that any living organism would be able to thrive in that water but those little Aplocheilus panchax I saw swimming proved that fish can live here.

We came here today to search for what many Thai fish experts believe to be a new species of fish in the Betta genus. I've seen the fish with my own eyes and there were enough differences in their appearances when compared to the known species of Betta. Still, I wanted to see the fish in their natural habitat to believe that they are really a new species, or whatever they are, but not a captive hybrid. Some said this fish is a released hybrid but if I can prove that their distribution is wide enough, we should have a new species of Betta right in front of our door. Mahachai is only 30 minutes drive through the express-way from Metro Bangkok - where 10 million people call home.

I started my search early in the morning when I visited a local Betta breeder's house. After a long conversation to convince him that we want to see the fish for the science’s sake and that we have no intention to collect the fish in large quantity, he revealed to us the place where we could find the wild Betta of Mahachai.

Back to the swamp, I finally decided to get into the water. We had come such a long way and it was no point turning back. Each of us has a big dipping net in our hand. We had no waders; a pair of sandals was all we had. To my surprise, the water didn't smell as bad as I expected. From my previous experience with Betta sp. in natural habitat, I found that they like to stay close to the bank where grasses and vines help them camouflage. We started there. After several dips we managed to catch a few Aplocheilus panchax - orange colour morph with black edging unpaired fin (simply striking!), Trichopsis vittatus and some small shrimp. We were not very impressed although the A. panchax was very nice.

After 15 minutes of continued dipping we got tired. I started to think of the information the group had gathered. We were told that this fish build their nests in between the palm petioles so, we started searching for the bubbles.

That was when I saw three local kids standing on the road shoulder and giggling at us. I could hear they say something like "Those city people will never be able to catch the Betta with those dipping nets."

"Ok, if you know how to catch them why don't you show us how?" I said to them.

They agreed and told us to help them look for bubblenest of the Betta between the palm's petioles.

They said that the nest of the Betta would be quite small and compact, if we found a big nest then it belonged to the Trichogaster trichopterus. So we started the search. After a while, one kid found a nest.

To my surprise, he managed to catch the Betta with his bare hands! I was very excited to see the wild Betta of Mahachai from their natural habitat for the first time. They look very much like B. imbellis with iridescent green colour at first glance, but a closer look at home revealed several obvious differences (more on that later). What I didn't understand was, what were they doing here in this central plain area that supposedly belonged to B. splendens?

Anyway, it is highly possible that this Betta is taking the ecological niche left empty by B. splendens that cannot tolerate the brackish water in this area.

The kids' method of catching the Betta was simple. He would close the nest entrance with his right palm. With the other free hand, he used a little stick to scare the Betta out of the nest. That way, the fish simply swam into his palm. The way they built their nest, that is so effectively guarding their nest from larger predator, became their trap with only one entrance. It sounded simple enough but it was not easy. Finding the nest was one thing - that was difficult enough - but catching them bare handed was even harder.

I shamelessly admit that after several hours of searching deep into the swamp where we couldn't even hear the noise of the 10 wheeled trucks rumbling on the road, I couldn't catch a single Betta !

We spent probably almost 3 hours in the swamp of Nypa fruticans. There were variety of birds, weird spiders and some insect that did bite. In the water, we caught Betta sp. Mahachai, Channa striata, Trichopsis vittatus, Trichogaster trichopterus, Anabas testudineus and Aplocheilus panchax. Most of these fish, except the Panchax which is a Killifish, were Labyrinth fish that have the special organ to breath air instead of breathing in water with low oxygen content. We also met with locals whose also come to the swamp for the Betta. Obviously, this place was no secret for them. Most of the people said they will use them in fish fighting. I noticed that everybody seems to be using the same method that our kids used. That is catching the male from its nest. Most of the fish we saw in their bags and bottles were males. I assumed that females must not be so far away so I used my big dipping net to swoop under the leaves and vines. In the process, I caught so many others fish I mentioned above but no sigh of female Betta. It was weird how difficult it was to find a female.

On that day, we went home with nine Betta sp. Mahachai and a lot of scratches here and there on our legs. To my delight, we later found that one Betta was a female. The water sample I took home had pH of 7.8. With a little salt in the water, B. sp. Mahachai is as easy to breed as all other Betta in the splendens complex. My one and only female would later breed to one of the males and some of the offspring have been distributed to some of my close friends. I later met with a guy from Mahachai who shared the passion in this wild Betta. We swapped our fish to increase the gene pool and the fish is now being distributed, quite the world over. Some wild-caught fish also find their way on to the shelf in Bangkok fish market occasionally. I gave some of my wild-caught fish to the expert at the Fishery Department for identification. It was later confirmed to me that this distinct population of Betta is very likely a new species but more "samples" have to be taken before the description process can begin. For good reasons, it is unacceptable to use captive bred fish for a species or sub-species' description.

Anyway, it is still unbelievable to many experts how such stunning fish manage to escape the science world for so long. Some argue that given how popular fish fighting in the area, this Betta might just be a hybrid of B. splendens and B. imbellis that have been released into the area. However, my local friend confirmed to me that the Betta is present in a quite wide area and they can be found not only in the Nypa fruticans swamp but also in several other types of habitat.

It is impossible for a hybrid population, that look exactly alike, to be that widespread, in my opinion. Their distribution range has to be determined before I can speculate further.

It is, however, pretty much confirmed that to the East of Mahachai is Bangkok where B. splendens were once found everywhere. Further inland is Rachaburi province, where I collected B. splendens last year. The only possible place that we might be able to find the Betta is the shore line, west of Mahachai - Samutsakorn province - in the province of Samutsongkran and Pethburi.

Plotting their distribution range will give me a very good reason to visit this area once again in the near future.

Their future:

I stated earlier that Mahachai is only 30 minutes away through a six-lane express-way from Bangkok metro. This area has gone under rapid development in recent year. Actually, the fact that the local kid was wearing Mc Donald's shirt and holding a plastic soda bottle in his hand should be evidence enough! Anyway, the swamps were filled and the factory is being built. Then the waste water from the factory is discarded into the swamp near by.

The swamps are also being cleared out for shrimp farming which has become one of the country's largest export item.

The area is undoubtedly under going a very rapid development and unless some kind of protection effort is being made to save the habitat of this unique Betta, the only place we can see them will only be in jars.

Direct impact on fish population is also under way. The way that the locals catch the full grown breeding adult males from their nest, sometimes destroyed the eggs and fry in the process, if this continues it will put a lot of pressure on the breeding success of the fish in the habitat.

A small population is also being isolated in a small local pond. I imagine that in the past, floods should occur in this river delta area every year. However, with several dams being built up-river and the road irrigation system, this flooding is not that common anymore. In the long run, without new genes getting into the population they will get weaker and subsequently die off.

The other issue is hybridization with domesticated strain of B. splendens.

In captivity, this fish can be freely cross-bred with B. splendens and give viable fry. So imagine what is going to happen if someone in the area gets bored or have too many B. splendens and decided to discard them into B. sp. Mahachai's habitat! Although the water quality will not really suit their like, some might survive and hybridization will occur. This is how we lost so many populations of wild B. splendens and B. imbellis.

It is very important to notice about the fact that this Betta can freely crossbreed with B. splendens. It shows that they are a very close species, just like B. imbellis to B. splendens. There has been long arguments of how valid the B. imbellis name is. Some argue that they might very well be just a colour variation of B. splendens, or at best they are just a sub-species. Could B. sp. Mahachai be the link to these two species or maybe both B. imbellis and B. sp. Mahachai can only be sub-species of B. splendens? I will leave that to the scientist to decide.

Another threat to this fish is the introduction of alien species. Under mosquito control program by a government agency, they foolishly introduced the Guppy, Poecilia reticulata, into the area (like the Betta is not enough for that). The fish adapt well to their new environment and are now breeding in large quantities in some of the ponds in the area. So far, I noticed that Oryzias melastigma, the local egg-laying fish that taking the same ecological niche with the Guppy, has completely disappeared from the pond where the Guppy is present. The Killifish and the Betta still hold their ground, but it is just a matter of time before the Guppy will dominate the water and drive the local fish to extinction.

Below is the comparison chart between four bubble nesters that can be found in Thailand from my personal observation. I'm not a taxonomist so please bear with me.