A Noisy Tankmate from the Island of Koh Samui, Thailand
Author: Ronny LundkvistFrogs aren't the only croakers in aquaria. Meet a noisy and supplemental-air-breathing species from Southeast Asia.
A Noisy Tankmate from the Island of
Ronny Lundkvist
In the late 1990s, I made a holiday trip to the
The Literature
It is hard to find literature describing the different fishes on a little island like this. In the excellent book The Fresh-Water Fishes of Siam, or Thailand (1945), author Hugh M. Smith mentions Koh Samui’s connection with some species that are not completely unknown to us: Betta taeniata (a mouthbrooding fighting fish), the blue panchax Aplocheilus panchax, the pearl danio Danio albolineatus, and the croaking gourami Trichopsis vittata. The observations had been made during the 1930s, and according to Smith, Betta taeniata was found both in mountain streams and in lowland areas in southern
Local Help
With this in my mind, I went away to look for the croaking gourami in its proper environment.
Language and Environment
Pla kat means “biting fish,” and is the common Thai name of the Siamese fighting fish Betta splendens. However, it is also used for similar species in which the males are more or less aggressive toward one another—especially in locations where Betta splendens is absent. Thus, on the
After a few minutes there were several croaking gouramis in the bottle. The boys caught them with their bare hands close to the shore and were meaning to use them as bait. I saw at once that they were croaking gouramis and asked “pla kat?” They then pointed eagerly to the west and mentioned the name of a city. At the same time a motorbike driver stopped and asked politely if he could be of any help. He told me that the Siamese fighting fish could be found further west but added that the fish in the bottle was also called pla kat in his home village. I did not understand if he meant that the common fighting fish was for sale in a marketplace or if there were wild specimens in the fields; there was complete confusion. However, I did later learn that both Betta splendens and Betta imbellis are native to the island.
Purchase and Analysis
I ended up buying the fish in the bottle—transporting them overseas was no problem, as they are an air-breathing species like other gouramis and bettas. The croaking gourami reaches about 2¾ inches, and when mating, the male often produces a loud croaking sound, hence the common English name. Being a rather shy species, it should be kept in a tank of its own or kept together with related species. Even though the pearl danio and the croaking gourami can be found on the same island, they do not share the same habitats. I found the danio below a waterfall, which is clearly not a suitable place to build a bubblenest.
This gourami is not overly sensitive to water conditions, as long as the temperature does not drop below 25°C (77°F). It seems to prefer mosquito larvae and other similar foods. Many bettas build bubblenests every now and then, but the croaking gourami seems to be induced to breed with little difficulty. The recipe involves a sunny position, thick plants such as Riccia fluitans at the surface, and temperatures of 28° to 30°C (82° to 86°F). It breeds in typical betta fashion, with the male embracing the female under the bubblenest. The young hatch after about 24 to 36 hours, and being very minute and delicate, they must be provided with the very finest grades of food. The young are very sensitive to low temperatures at the time of the formation of the labyrinth organ (the breathing organ), at about two to three weeks after hatching.
Conclusion
Although I searched in mountain brooks, I did not see Betta taeniata. Aplocheilus panchax also escaped my eyes, even though the species is easily recognized by the white spot on the head. According to Smith, it was very abundant in the 1930s in the lowlands of the island. However, many areas have been drained since then for the building of hotels and for other reasons. If you are looking for native species in
Reference
Smith, H. M. 1945. The Fresh-Water Fishes of
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