by Tan Heok Hui
This is the first of three accounts of trips to Sarawak to collect fish specimens. It also marked my first experience fishing with the world-renowned ichthyologist, Dr. Maurice Kottelat. Our main purpose was to obtain the fish record from the blackwaters of Sarawak, a project supported and approved by the Sarawak Museum. Our secondary aim was to collect all belontiids found in Sarawak. In many ways., it was a success but in some ways, it was the failures which inspired the following trips.
Being a first-timer in Kuching, I made a visit to the Sarawak Museum. It had excellent exhibits of cultural and archaeological interest. The natural history section was also quite an eyeful, with its many endemic mammals and birds of Borneo. The museum gift shop had a good selection on the natural history of Sarawak and Borneo. I spent some time taking in the sights of Kuching – river front shops, statuettes of cats (kuching in Malay) and Sungei Sarawak, which fronts the main street of Kuching town.
We set off, bright and early for Sibu, a largish town in central Sarawak. The highway connecting Kuching to Sibu was under repair and construction in certain sections, the road was basically untarred and full of stones. Most of the time therefore we received posterior and occasional full-body massage for kilometres on end!! The weather was fine and very hot (~34°C), hence it took us a full day to reach Sibu.
The first site that we sampled was a relief from all that travelling for us. It was a blackwater stream about 100m away from the sea, at about 28 km from the coastal town of Mukah. The water was really cool and refreshing (~22°C) and from its reflected surface, it looked like a stream of Coca-Cola but with a pH of 5.0. There were no aquatic plants but bank vegetation had overgrown into the water which was about 1.2 m deep. The belontiids caught were Betta akarensis and Parosphromenus allani. However the site was otherwise quite species-poor with a total of only five other species.
The next site (~34 km from Mukah) yielded Betta akaransis and Luciocephalus pulcher. The water was also black and of pH 5.3. There was intact forest ~200 m parallel to the road. The last site for the day was about 40 km from Mukah. It was a brown-water forest stream of pH 5.6. There was luxuriant growth of Barclaya motleyi and Cryptocoryne sp. This site had many Nandus nebulosus and some Betta akarensis. From some wooden platforms at the bank of the stream, it was clear that it was used by the locals as a bathing place – that explained the presence of excessive algal growth and aquatic plants.
Today we tried the outskirts of Sibu town, near the airport. We discovered that the airport had been built over a peat swamp forest. All the streams in that area were blackwater and some were highly polluted, especially those running next to the chicken farms. The chickens were kept in long, bunk-like structures, which we called ‘chicken long-houses’. These streams were full of the refuse of the farms, like feathers, occasional carcasses and offal. We could smell such streams before we actually sighted them.
Luckily, there was a clean stream at the northern end of the airport. The pH of this steam was 4.9 and there was Barclaya motleyi present. We caught Betta akarensis, Parosphromenus allani, Trichogaster trichopterus and T.pectoralis. This was a memorable site because I was stung by a hairy caterpillar feeding on the bankside. vegetation.
The next site was a small river, north of the Durin ferry point toward Sibu. This was also blackwater and with a depth of 1.5 m. Here we obtained Parosphromenus allani and Betta akarensis. A new species of puffer fish, described by Kottelat and Lim (1995) was also caught – Carinotetraodon salivator. It is a dwarf species and reaches an adult size of about 5 cm standard length. Rasbora axelrodi was also found here in small shoals. These are interesting fish with a somewhat similar coloration to the Neon Tetra, hence the name we gave it, the Neon Rasbora.
The following site was a shallow, brown-water stream, running out of an old rubber-tree plantation. There was luxuriant growth of Barclaya motleyi and Cryptocoryne sp. in the stream. The Barclaya was in full bloom and ripe fruits were also observed which looked like a purplish bulb. Only Betta akarensis was obtained from this site, along with a few other species of cyprinid.
On the way back to Kuching, we tried to catch Betta taeniata following the location data found in Brown and Brown (1987). We tried to decipher the data and after several interpretations and meandering into side roads, we decided to call it a day after much frustration. We only managed to sample one site which yielded no belontiids. Although we came across some habitats that seemed suitable for Betta brownorum, we did not catch any.
Once back in Kuching, we managed to spare some time visiting the antique and book shops. A wide array of Iban and foreign handicrafts can be found here. From this trip, we had learned to take other peoples’ data with a pinch of salt because human development had changed things so much. The next trip would be different!