Kanchanaburi in western Thailand is close to the border with Myanmar and is an area of ​​great biological interest. I have been visiting this place frequently for quite some time to take photos and observe the creatures.
When you go to this area, you will pass through Dongbapun, the crab town that was introduced in this column previously. From there, we drive through the mountains for about an hour and arrive at the town of Sangkhlaburi, which can be considered our home ground.
If you take a different route up the mountain from Thongpapun, you will reach a small mountain town called Piloc. This time, this place called Pillok will be the main topic of discussion.

I first came to this place called Pilloc more than ten years ago to photograph the Schistura balteata as it was home to this place. I remember seeing Balteata Roach in a fairly high density in mountain streams. However, strangely, the only other fish found in this habitat are one species of giant danio (Devario. sp.) and the dwarf snakehead (Channna limbata).
Normally, rivers with abundant nature and lots of fish often see shrimp and other creatures, but here they are nowhere to be seen. As someone who likes to see many kinds of fish, this is not a field that I often visit. When a Japanese S photographer came to Thailand about 6 years ago, I showed him around.

Last spring, I visited this place for the first time in a while. I remember that the water in this habitat was very clear.
Recently, he has been making videos of underwater scenes in Southeast Asia. This is not a full-fledged video for television, but a video taken with a compact digital camera, but the image quality is high enough to be viewed on a computer. So I felt like taking pictures again in the clear habitat of Balteata Roach.
I went to a different stream from the one I visited before, but this one was narrower and more convenient for photography. If you look into the pools of mountain streams, you will see Balteata roaches fighting for territory here and there. The population density seemed to be quite high, just like in the past.
When visiting over the years, one is often disappointed to find that the habitat has changed drastically, but here there was no need to worry about that. I completely forgot about the passage of time and enjoyed underwater photography.

In January of this year, there was a machine that visited the Balteata Roach habitat in Tonpapun again. Many people think that Thailand, which is a tropical country, is hot all year round, but from December to January, the temperature drops considerably here, just like winter in Japan. This is especially true in mountainous areas at high altitudes. The water temperature in the river at this time of year is probably below 15 degrees Celsius.
When I dipped my feet in the water, it was so cold that I couldn't stand it for very long. When I experienced this water temperature myself, I wondered if there was a Balteata Roach in this cold water. My anxiety finally passed.
As expected, when I put in the net, none of the fish that were so densely populated and easy to collect came in. Activity probably decreases during periods of low water temperature. Even if you look closely into the water, you can barely see it. I thought it would be impossible to take pictures at this time of year, but my partner Ton, who came with me, got excited and called out to me. When I rushed there, I found an unfamiliar fish in the net! ! If you look closely, you'll see that it's a Balteata Roach, but its entire body is bright yellow. The body color has not changed, but it is clearly a color variant individual. I've been watching fish for many years, but I've never seen a yellowish type of loach other than the Japanese loach. If you compare it to a fish with a normal body color, the color is clearly different.

We are lucky to be able to collect golden Balteata roaches early in the new year. As I continued to collect fish, the number of fish increased as the sun came out in the afternoon and the water temperature rose. As expected, when the water temperature is low, they hide under stones and do not seem to be very active. This golden Balteata Roach was treated as a super VIP and safely brought back to Japan. I had been breeding him with the intention of photographing him once the scratches on his fins and body had healed, but unfortunately one day he suddenly died. Of course, I haven't taken any pictures yet. How many times have I regretted taking pictures before I die?

This time, at this location, I made another important discovery. When I was kicking stones in the mountain stream to collect food, a small crab came into my net. The density of crabs in this area is low and they are rarely seen. It seems to live under stones near the shore, and can be found by raising the stones in that area. At first, I thought it was a baby freshwater crab, as its shell is only about 2cm wide, but it looks different. After catching a few fish, I looked closely and noticed that, despite their small size, the male's pincers were greatly developed on one side. In young crabs, there is usually no difference in the morphology of males and females. This means that this crab is considered to be an adult at this size. I have seen many freshwater crabs, including Japanese river crabs, in various parts of Southeast Asia, but the only adult crabs of this size are members of the Geothesarma family. This crab has also been carefully brought back to Japan and is currently being reared, so we may be able to report on it again someday.