Even if you keep familiar fish, you will discover many new things when you keep them. That is the real thrill of breeding. I made a new discovery about Orysias mekonensis that I collected in Udon, northeastern Thailand, about a year ago, so I would like to introduce it here.

The genus Orygias, which includes the Japanese killifish, is a group distributed mainly in Asia and includes many species. It is an interesting genus with new species being described recently. The genus name Origias is derived from Oryza, which means rice. Many species of this genus inhabit paddy fields and their surrounding areas, and this is because they are closely related to rice.
Among them, the fish I am most interested in are the small fish of the genus Origias, which are distributed in Thailand and Laos. Oryzias minutilus, also known as the Thai killifish, Oryzias mekongensis, also known as the Mekong killifish, Oryzias songkhramensis, which I have previously introduced in this column, and Oryzias pectoralis. Although it has been described, from what I have seen in the field, it seems that as research progresses, it will continue to be subdivided and new species will increase.

When I introduced Orygias songcramensis in the first part of this column, I mentioned that it is difficult to identify the type of this small Orygias, which has a similar appearance, by simply scooping it up outdoors with a net or putting it in a plastic bag. I learned something difficult. Since then, I've been trying to take them home and put them in the aquarium and observe them. This way, you can pay attention to differences in details that are often overlooked, and you can also see colors that only appear when conditions are optimal.

In October 2016, I went to the northeastern part of Thailand to check out the Betta Smaragdeina guitar, which I have already introduced in this column. On the way back, I took a short detour to a town on the border with Laos called Udon. Of course, the purpose here was to collect Betta smaragdina, but the main purpose was to collect Boraras micros.

This is the phantom Boraras, which has almost disappeared from the ornamental fish route in recent years. My buddy Ton remembered collecting some here in Udon before, so I asked him to guide me there. The first thing that caught my eye at the wetland, where beautiful clusters of wild water lilies were visible, were Orysias mekonensis swimming in groups on the surface of the water. Unlike bettas and rasboras, which you can't tell if they're living without a net, Origias swim close to the surface of the water, so they're easy to spot. Origias seems to be easy to collect, so I'll put off collecting them later. First, I started collecting Betta smaragdina. The Smaragdina here in Udon is a beautiful green color, and the bright red of its pelvic fins is impressive. Trichopsis chaleri also came into the net, but its body color was normal and it was clearly different from the one in Lake Bung Kong Long.

It is impossible to collect Boraras micros, which is the main purpose, just by casting a net from the shore. Because they live near the bottom of the water, they can only be collected by submerging themselves in water up to their waists and using a net to probe the bottom. Even so, each net can only catch a few fish, and it takes quite a while to collect nearly 100 fish. After learning about the inefficiency of their collection, I could understand why the ornamental fish route was no longer available. If they were set at a low price just because they are small in size and come from Southeast Asia, Boralus micros and Orygius mekonensis would not be good for commercial purposes at all, so there would be no suppliers to collect them. . These small fish require more delicate collection and care than larger fish, and are more time-consuming. If that is not appreciated, it is only natural that there will be no one left to continue.

Now, this is a long digression, but I left the difficult task of collecting micros to Ton, and I started my main job, which was photography. The water at this location has a slightly yellowish tinge, but it is highly transparent with little floating matter. Underwater photography is also possible here. I used a waterproof compact digital camera to take pictures underwater and video of Mekonensis. However, while filming, something unusual happened! The digital camera screen became monochrome and noise started to appear. When I checked, water had leaked in from somewhere and had gotten inside the camera. This is the end of electrical products. After that, it stopped working at all. Most importantly, the SD card containing the shooting data was intact. After opening the back cover of the sunken compact digital camera, drying it in the sun, and drying the inside overnight with a fan, it started working again, but I couldn't trust it, so I had to buy a new compact digital camera.

Although there was some confusion, Miklos and Mekonensis were safely brought back to Bangkok, where they were kept as VIPs in their hotel room until they returned home. The bait was finely divided tetramine, but there was almost no change in Micros, but Mekonensis was getting bigger day by day, and the red color on its tail fin was becoming more noticeable.
As far as I was concerned, I thought that Mekonensis had only red on the top and bottom of the caudal fin, and Pectralis had thick black inside that red. In fact, sometimes at the Sunday market, Origias, which is a conspicuous red and black color, is sold, and although the origin is unknown, I thought it was Pectralis. However, the mekonensis we collected this time in Udon only has red on its tail fin during normal times, but when it is in heat or fighting, there is clearly black inside the red. He had bred Mekonensis many times before and never noticed this. If so, what is the boundary between Mekonensis and Pectralis? ? ? Become. Once again, I wanted to check not only the mekonensis in Udon, but also the mekonensis in various parts of northeastern Thailand. That being said, I will be heading to Thailand and Laos again in October this year, so my challenge is to re-check the small Origias. By the way, Mekonensis, which I carefully brought back to Japan last year, was adopted by two friends and is being kept with great care. Unfortunately, it does not seem to be available on the market as it does not grow in large quantities.