Kalimantan Expedition: Sphaerichthys selantanensis (Chocolate Gourami)

Kalimantan Tengah

Kalimantan Tengah was our third stop on our journey through Southeast Asia. From Bangkok, we flew to Jakarta and from there to Palangkaraya. The flight took only 2 hours. From this city, we then made expeditions in all directions.

Kuala Kurun

The trip to Kuala Kurun, about 100 km north of the mentioned city, was very interesting. Here, we spent the night in a very pleasant hotel. From there, we headed almost 80 km west, where we came across an extremely interesting biotope. It is a place where not only our guide Hendra goes, but also other hunters who fish for him for export. A place where there were really plenty of fish. A stream, sometimes a small river, with dark black water slowly flowed under a narrow asphalt road. The chemical parameters of the water were interesting to us, temperature 30 °C, pH 5.68, and conductivity 52 µS/cm. Even more interesting was the quantity of fish and the wide spectrum of species we caught here. In Borneo, we mainly fished for Parosphromenus species, so our main interest was focused on blackwater biotopes.

Sphaerichthys selantanensis (Chocolate Gourami)

Here, we caught a not very well-known gourami, Sphaerichthys selantanensis (Chocolate Gourami). It was originally considered a subspecies of Sphaerichthys osphromenoides. These are mouthbrooding gouramis, whose fry are kept in the female's mouth. The other two species, Sphaerichthys vaillanti (Vaillants chocolate gourami, Samurai gourami) and Sphaerichthys acrostoma (Pointed-snout chocolate gourami), differ in that the male takes care of the brood. I first observed the breeding of Sphaerichthys selantanensis (Chocolate Gourami) in 2009 at a friend's place, who kept the fish in a species aquarium, in very soft water and with dense planting of Cryptocoryne. The hatched larvae measured 4 mm, after a week about 7 mm, and after 3 weeks already 10 mm.

The female took care of the brood for a full 2 weeks. At that time, I agreed that I wanted to see these fish in the wild. Now this old dream has come true. Subsequently, they swam with their offspring in my aquariums for years.

Aquarists from Kalimantan

Our guide, aquarist, hunter, and trader Hendra is a very interesting person. His original profession was an electrical engineer. With this profession, he wouldn't earn much in Kalimantan. Throughout the time, I talked to him intensively about fish breeding, and we got along very well. For example, for catfish of the genus Clarias and for goldfish, he mostly uses pituitary gland, for Rasbora kalochroma, which he breeds in large numbers in his hatchery, he has 200 eggs per spawn.

Images:

1. Sphaerichthys selantanensis (Chocolate Gourami) – almost adult male
2. A stream, sometimes a small river, with dark black water, which slowly flowed under a narrow asphalt road. The humidity and heat were significant, our functional clothing was an advantage.
3. First catch of Sphaerichthys selantanensis (Chocolate Gourami).
4. We transported the caught fish to the hotel in regular plastic bottles of drinking water.
5. Together with Sphaerichthys selantanensis (Chocolate Gourami), we also caught many Barbus rhomboideus (Rhomboid barb). These barbs inhabit black and clear waters and breed quite easily in captivity.
6. Of the fighting fish, Betta anabantoides (Giant betta, Pearly betta) most often got caught in the nets.
7. Rasbora kalochroma (Clown rasbora) is a beautiful and very lively fish inhabiting black and clear waters.
8. We saw some loaches for the first time in our lives.
9. The most frequently caught members of the Hemirhamphidae family were Hemirhamphodon tenga (Tenga halfbeak).
10. Representatives of the genus Homaloptera also live here.
11. The family Mastacembelidae had its representatives.
12. We were surprised by the recently discovered "neon rasboras".
13. In some parts of the stream, large schools of Sundadanio axelrodi (Axelrod's danio, Blue Axelrodi) swam. These fish were originally known under the genus name Rasbora.
14. Several unidentified catfish also live here.
15. Many different shrimp also lived in the stream.
16. The water temperature was 30 °C, pH 5.68, and conductivity 52 µS/cm.
17. It made me happy that Hendra very often borrowed my practical black net.
18. Hendra carefully examined all the catches.