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Sarawak Quest 3

by Tan Heok Hui

This third trip to Sarawak proved to be most fruitful- Betta brownorum found and a range extension. This Betta was found, partly due to a fishmonger - of all people! Previous data was again heeded initially, only to be eventually disregarded due to seasonal changes in habitat. This trip once again concentrated around Kuching.

Day 1
We arrived on a Saturday, to be in time for the weekend market. As usual an eventful start, as no vehicle was available from the hire company, although bookings had been made. At the last minute, we managed to get help from a friend, who kindly ferried us to and from the sites on this first day. We sampled the Matang area blackwaters again, in hope of finding the elusive Betta brownorum. Witte and Schmidt (1992) had reported its existence in this area. We were quite confident of finding it there but the monsoon season compounded our problems. The water level was high and the forest inundated, living up to its name of swamp forest. The water was black like Coca-Cola, with a pH of 3.7 and a peaty bottom. We managed to catch Betta cf. akarensis, Luciocephalus pulcher, Nandus nebulosus, Channa bankenensis andC.lucius. Oddities included Parakysis verrucosus and Lepidicephalichtyes pristes.

We also managed to check out the weekend market at Jalan Satok. there was much local produce on sale amongst the organised chaos. Temporary aquarium stalls had been set up and they were selling exotics like Texas cichlid, Blood Parrot (hybrid), Goldfish, Angelfish, Discus and Betta splendens. There was no trace of any local species, though the food fishes, Anabas testudineus and Channa striata were present. We tried to find Sago worms but were not successful. We also tried out other local delicacies and snacks. Unusual native fruits and vegetables abounded. That evening, we managed to get our vehicle and transportation was solved for the following days.

Day 2
We headed out toward Serian town for breakfast on Sunday morning. There were many special goods on sale in the market - we caught glimpses of Mouse deer, Pangolin, Civet Cat and Hill Mynah, all alive and probably sold as food or pets. There were numerous bundles of young fern fronds on sale. This pteridophyte is usually eaten fried with chilli and fish paste and a very popular vegetable dish in Sarawak. Be forewarned that excessive consumption is detrimental to one's health, because this fern contains certain toxic alkaloids.

In the wet market, we met a friendly fishmonger who sold exclusively local produce, especially freshwater fish. These fish were caught by the locals from around the area and were then collected by the fishmonger, to be sold in the market. Among the species being sold, were numerous large specimens of a blackwater clarid-Clarias nieuhofi. We then struck up a conversation regarding the origin of these specimens and found out that they originated from the blackwaters around Gedong, a town not far from Serian. Other food fish included Channa bankanensis, C.lucius, C.baramensis and Hemibagrus sp.

We then headed out toward the Betta taeniata site to collect more specimens. This time around, we went in further and came across a village. There was a small tributary, running along the edge of the village. The water was clear and flowing quite fast. The lower reaches abounded with rubbish, typical of streams near villages. The substrate was sandy and the water of pH 6.2. We only sampled the upstream area and sure enough, Betta taeniata could be found here in higher concentrations than at the site which we had sampled previously. Within an hour, we had collected as many specimens as before including a mature, mouthbrooding male.

As the priority of this trip was to collect Betta brownorum, we decided to head toward the Matang area, where there was proof of capture, rather than trying out a new locality. With hindsight, this was a mistake which was realised only on our last work day. The water level in the peat swamp forest had risen to waist depth (~1m) in certain areas. We had previously sampled around this general area during the drier season, when the ground underfoot was moist and with few pools of water. This time round, these areas were fully inundated, from 40 to 100 cm deep. In this flooded forest of blackwater (pH 4.0), we managed to catch Rasbora axelrodi, Rasbora pauciperforata, Betta cf. akarensis, Luciocephalus pulcher andChanna bankenensis. As the sky darkened, due to the approach of dusk and rain clouds, we moved out, shivering, from the cold and headed back to Kuching for a warm bath and a meal.

Day 3
This was one of the most miserable days as it rained cats and dogs intermittently. We travelled to Kota Samarahan and back to Bau-Lundu area. All the waterways were flooded and some had even burst their banks and flooded the adjacent fields. Some of these rivers were clear water and shallow during the dry season but they were now murky and much deeper. The murky water surface boiled with the undercurrent and a tremendous amount of water was washed down. It was dangerous to attempt sampling in such conditions. Some of the rivers were so flooded that locals were using outboard motors to travel, instead of the usual paddles and oars. As it continued to pour, we decided to cut short our meandering and returned to Kuching for an early dinner.

Day 4
This was our last sampling day and we set out with fingers crossed. We travelled all the way to Gedong, a small coastal town with the typical round-about in the middle of town. All the rivers near the town were mangal (mangrove) so we headed back and sampled the most promising site. It was a similar-looking habitat to the Matang area peat-swamp forest, except that the water level was not so high. The ditches parallel to the road contained fast-flowing blackwater, just like Coca-Cola. These ditches had little life in them, being too fast-flowing. We proceeded into the forest where it was mushy and wet underfoot with occasional pools. We sampled at these earlier pools but only caught juvenile Clarias nieuhofi andC.teijsmanni. At one of these deeper pools we hit pay dirt- Betta brownorum but we did not get many from these stagnant polls, they were probably just washed out.

We penetrated deeper into the forest in search of the home ground of B.brownorum, ignoring the biting midges, thorny rattans and spiky pandans. We hit B.brownorumcountry!! At almost every dip of the net, we caught B.brownorum. In quiet pools, with dappled sunlight streaming in from the canopy, we could actually observeB.brownorum swimming just above the substratum. When we had caught enough, we headed out contentedly but another surprise lay ahead of us. Among the juvenile clarids that we had caught, there was an atypical specimen with a rounded head and a conspicuous adipose fin. It was an extremely rare Encheloclarias baculum. This was the only known specimen, apart from the Bleeker holotype. What a coup! We had succeeded beyond our dreams. Not only had we obtained the last elusive Betta species to be found in south Sarawak, we had also bagged a rare clarid. We hastily packed up and headed back to Kuching for a celebratory dinner.

Day 5
With our mission accomplished, we did some shopping before flying back to Singapore with our precious specimens. From the cumulative data of the previous trips, there are currently four species of Bettafound in south Sarawak (six in total from Sarawak). Of these four species, two are new to science (see future issues for an update).

From these trips, I observed that most waterways near the highway are polluted and the surrounding forests logged and transformed into plantations, industrial and residential areas. In some areas, the forests are mere glimpses at the edge of the horizon. Only in the back country areas are the waterways less polluted, with a richer fauna.

These collection trips are for scientific purposes and specimens collected deposited in the Zoological Reference Collection, Department of Zoology, National University of Singapore, with voucher specimens in Sarawak Museum.

 

Acknowledgements

I thank the following: Dr Peter Ng, for his inspiration, Dr. Maurice Kottelat, for his guidance, Dr. Charles Leh, for his permission to collect in Sarawak; Daphne Chung, Ng, H.H., Tan, S.H. and Darren Yeo for their help in the collection and transportation in Sarawak.

References

1. Brown, A and Brown, B. 1987. A survey of the freshwater fishes of the family Belontiidae in Sarawak. Sarawak Mus. J. 37, 155-170, 3 pls.


2. Linke, H. 1990. Labyrinthfische- Farbe in Aquarium. Tetra Verlag, Melle, Germany, 140 pp.

3. Witte, K-E and Schmidt, J. 1992 Betta brownorum, a new species of anabantoids (Teleostei: Belontiidae) from northwestern Borneo, with a key to the genus. Ichthyol. Explor. Freshwaters 2, 305-330.

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