Belulok Waterfall stream of Labi, Brunei Darussalam

83rd place in Biotope Aquarium Design Contest 2017

Brunei Brunei. Mohammad Zaheer Afie bin Zahirrudin

Volume: 96 L
Dimensions: 75x36x36 cm
List of fishes: Betta macrostoma, Nandus nebulosus, Rasbora einthovenii, Rasbora kottelati, Puntius pentazona
List of plants: Cryptocoryne longicauda
Description of decorations: Decoration & Substrates are all directly taken from Labi jungle. Substrate is mainly made up of Clay, with a minor mixture of sand & silt from decayed leaf litters, various sand stone sizes & some broken branches to replicate branches that fell from the tree tops to the stream. Driftwood was 1st placed to mark the growth of the C. longicauda, but overtime, they crept from under the driftwood & covers part the wood, just as in the wild
Description of equipment: HOB Eheim Liberty 200 (can produce flow of 320 to 760 L/Hr, but can be restricted by a valve before the impeller of the filter), BeamsWork Super Bright LED Clamp-on Aquarium Light Fixture (0.5 watt LED each, 21x 10000K LEDs, 3x Actinic 460nm LEDs), Jebao aquarium fan cooler (to lower down the temperature of the aquarium water)
Water parameters: Temperature: 25°C, pH: below 6

Description of the area surrounding the biotope: Belulok, located deep in the jungles of Labi, Belait District, Brunei Darussalam, is one of many waterfalls. Labi in Brunei is considered a highland area due to it having a high hilly terrain. The top of Belulok waterfall itself has an elevation approximately around 450ft. Belulok Waterfall is situated along the Belulok River. Where the water falls, is surprisingly a stagnant pool, whereby the water is blocked by big boulders from the surrounding wall of the hill, the waterfall pool is a “Safe Haven” / “Breeding Ground” for B.Macrostoma, as they are the only fish species that exist in that pool directly below the waterfall. About 50 metres down from the boulder path, a stream can be found leading to a small pool about another 30 – 50 metres & that pool, is home to hundreds, if not thousands of Rasbora Einthoveni, Rasbora Kottelati, Puntius Pentazona, & many more.

Description of the underwater landscape of the biotope: Located within 100 – 200 meters from the 1st downstream pool of Belulok Waterfall, lies a small side stream where Cryptocoryne longicauda grows abundantly due to the area being heavily shaded and the soil being mostly consisting of clay rather than sand, whereas at the main Belulok river, the substrate is mainly made up of sand than clay, this is because, the surrounding hills (boulders & cliffs) are made up of sandstones. The Cryptocoryne only stops growing at the starting of the side stream when it meets the Belulok river, assuming that it is because there is more sand now than there is clay. The substrate where the Cryptocoryne grows are Yellow clay, where as the Belulok river is made up of a mixture of clay & sand, & sand stones of various sizes, leaf litter, branches & driftwood could be seen along the stream. In this area, Rasbora kottelati & Rasbora einthovenii could be seen schooling together by from sometimes a few to a hundred, a few adult Betta macrostoma would usually be lying on the substrate or hiding under leaves, Puntius pentazona would be pecking on the substrate of the river, always in search of food.

Description of the parameters of the habitat: Water is clear, but some clay debris may float after rain or when disturbed. Temperature: 23°C – 24°C, pH: Less than pH 6

List of fishes: Betta macrostoma, Rasbora einthovenii, Rasbora kottelati, Rasbora cf. tornieri, Rasbora cf. cephalotaenia, Puntius pentazona, Puntius binonatus, Nandus nebulosus, Hemiramphodon pogonognathus and an unidentified species of Siluridae catfish.

List of plants: Cryptocoryne longicauda & Barclaya motleyi on the substrate of the river, & Aridarum caulescens, mosses, ferns & a species of Bolbitis are found on the rocks, usually above water level.

Threats to the ecology: This setup is to help raise awareness about Betta macrostoma, also known as the Brunei Beauty. B. macrostoma is considered to be one of the most expensive wild bettas in the aquatic industry all over the world as the species is only found in Labi Brunei & Marudi, Sarawak, Malaysia. Wild specimens have more high demands than the domestic bred ones, as they tend to lose their colour without the proper care or diet. Without proper education on the species towards locals & without highlighting their areas of distribution, this species could face risk to extinction from unsustainable catching/over catching, deforestation/development of the forest, or just simply pollution by tourist who are coming to see the waterfalls located around Labi, Brunei. Although it is said that this species is protected in Brunei, but from various trips around Labi area it seems as this protection act is not really enforced as no law enforcement workers could be seen around the area, and it so happens that there could be seen a few people who are catching this species, when asked, some like to catch these fish, but have had unsuccessful stories on keeping them for a long period of time, some even said they have caught more than 18 pcs of macrostoma within one day. It is sad to see this happening, & hopefully people would see more of the beauty of the macrostoma in a biotope setup and how a lot easier/low maintenance & happy the fish is in these kind of setups.

Sources of information: Self Research from multiple trips to Belulok Waterfalls, ,