In mid-June, when the rainy season had begun, I went to Kanchanaburi in western Thailand to take photos near the Myanmar border.
However, the water in the river had swollen due to continuous rain and was muddy and muddy, making it impossible to photograph fish. Although the rainy environment is not suitable for photography at all, the rain is a boon for living creatures, and some creatures are only active during this season. Look for such creatures during the few sunny spells that occur between rain showers. Insects that can often be seen during this season include wild crabs, frogs, and Japanese poplars. Frogs are very active during the rainy season, and at night the waterfront is quite lively with their mating calls. At this time, unlike usual, they were surprisingly less cautious, and it was possible to get close and photograph them.
White-legged frogs are laying eggs on tree branches, and in the water, Asian-legged frogs are making low growling sounds.
I'm not an expert on frogs, but when I see them like this, I can't help but want to photograph them. The Tamayasuide family, which has recently become popular as a pet in Japan, becomes active and appears on the ground during this season in Thailand. During other seasons, they live under fallen leaves or underground, making it difficult to see them. During this season, Japanese poplars emerge from the mountains and often cross the road, so much so that they can be seen from cars.

Well, the main purpose of this trip was to photograph the mountain crab family.
The wild crabs, which usually live in holes in mountain streams, actively come out of their holes and do activities during this season. Although they are mainly nocturnal, they can be seen during the daytime in the dark forests during this season. I have photographed various mountain crabs, but I have never seen the Masked Face Mountain Crab in its natural habitat.
This species appears to only inhabit western Thailand near the Myanmar border. Mr. Tui, a local whom my buddy Ton always asks to collect fish, guides us to where the fish live. Guides who are familiar with the local topography are reliable.
The border between Thailand and Myanmar is complicated in this area, so you may find yourself entering Myanmar territory without even knowing it.

The locals seem to pay little attention to the existence of borders, but by looking at the letters on the signboards, it is easy to tell whether they are in Thailand or entering Myanmar. The place Mr. Thuy took me to was a place that looked like a narrow stream flowing through the mountains. It is a place that you will never find or enter unless you are guided.
Fortunately, the rain has stopped, so I apply plenty of insect repellent lotion and head out there. After a while, Tui got his first Masked Face Mountain Crab! There are crab holes all over the slope in that area. be quiet! As I walked along, I saw a crab with half of its body sticking out of the hole. I approach to take a photo, but the sound of stepping on a twig and making a snap causes it to burrow into its burrow. I get frustrated when I can't get a good scene, but patience is important when photographing living things.
For about 30 minutes, I walked through a stream that was barely wide enough for one person to walk, and as I observed the crabs, I noticed that the masked face mountain crab, which should have been bright orange or vermilion, had a dull color for some reason. I noticed something. At first, I thought it was an old adult, perhaps because it was dirty with mud, but it looks different. When I caught one and looked at it closely, I was convinced that it was a different species, similar to the Masked Face Mountain Crab, but with white claw legs and other differences. His partner Ton seems to have noticed this too.
I never imagined that two similar types of wild crabs lived in the same place. For now, I'll look up the scientific name later, and for convenience I'll call it White Arm Mountain Club.

This new face mountain crab is quite different from the masked face mountain crab not only in appearance but also in its personality.
The Masked Face Mountain Crab has large scissors, but it is relatively docile and rarely attacks, but the White Arm Mountain Crab has a fierce temper and will quickly attack with its scissors. .
When I let my guard down and caught it, thinking it was the same as the Masked Face Mountain Club, my finger was pinched so much that it bled, and I learned this firsthand.

As I closely observed their habitat, I noticed that the two species were living well together.
It seems that the Masked Face Mountain Crab is making a burrow closer to the water, and the White Arm Mountain Crab is making a burrow a little further away from the water.
It can also be observed in captivity, with the Masked Face Mountain Crab often found in water, while the White Arm Mountain Crab prefers land.

I have been coming to this place for almost 10 years to observe other mountain crabs such as the Masked Face Mountain Crab.
Why didn't I notice the existence of this White Arm Mountain Club? When I asked Mr. Tui, who guided me this time, he seemed to know about the existence of this mountain crab.
However, the Masked Face Mountain Club is the only place he orders from for work, so he didn't think the dull-colored wild crab would sell well. It was a huge blind spot.
This made me reaffirm that I have to see with my own eyes the places where living things live.

Excited by the discovery of a new species, I was about to continue photographing when the sky suddenly became dark. Suddenly, heavy rain began to fall. With this heavy rain, there was no time to take pictures. I wrapped my camera in a towel, used a banana leaf as an umbrella, and headed back along the stream. The rain was heavy, and the stream that had progressed quickly became muddy and muddy as the water volume increased. The dry places we were heading to turned into rivers, and we hurried along the muddy road to escape from the stream.
This time I was lucky because it was a small stream, but if it had been a large stream deep in the mountains, I might have been washed away by the rising water. This made me reflect on the fact that we should never underestimate nature under any circumstances.

Due to this situation, I was not able to take pictures to my satisfaction, but next time I would like to prepare a scope-type camera that can take pictures inside the hole.
The four fish we caught this time were safely brought back to Bangkok and photographed, so we would like to introduce them here along with their appearance in the wild.
If you are a member of Masked Face Mountain Club, I will introduce you to them the next time I am able to take a photo that I am satisfied with.