HABITAT - Malaysian Biotope

Malaysian Biotope

by Melanie Newfield

My motivation for my Malaysian biotope tank was spotting a fish I’d never seen before at my local pet shop. It was a small, silvery fish with a vivid blue eye, labelled as an “emerald eye rasbora”. A quick Google search, while I was standing in front of its tank, told me that the scientific name was Brevibora dorsiocellata, and that it was native to parts of Thailand, Malaysia, and Indonesia. I was already looking to create a tank for my pearl gouramis, and I wondered whether this delightful rasbora could go with them. Both species were reported to occur in lowland swamp habitats, which suggested that the two species could be found together. But I was aiming for a more specific type of biotope than just species that came from the same type of habitat in the same country. I was hoping to create a biotope based on a specific location, such as a stretch of river or a lake.

The Seriously Fish website (www. seriouslyfish.com) gave a number of specific localities for emerald eye rasbora, so I started with those. Very quickly, I had a lucky find. Tasek Bera (Bera Lake) was one of the localities listed by Seriously Fish. And I found a paper, available free online, with the

title “Ichthyofaunal diversity of Tasek Bera Ramsar Site” (Fahmi-Ahmad et al., 2015) - in other words, a list of the fish species found at Tasek Bera. “Ramsar” is a reference to the Convention on Wetlands, signed at a meeting in Ramsar, Iran, in 1971 and a “Ramsar site” is a wetland that is designated to be of international importance under the criteria agreed at Ramsar. The Tasek Bera species list confirmed that Brevibora dorsiocellata was found there and also listed Trichopodus leerii, the pearl gourami. My plan to create a biotope for the two species was off to a great start. I spotted something else that I recognised on that species list too - Pangio semicincta. This is one of the species known by the common name “kuhli loach” and the one most commonly available for sale. I adore kuhli loaches and decided that these would be a good addition to a biotope with pearl gouramis and emerald eye rasboras because they would occupy a different part of the tank.

So now I knew the combination of fish I wanted and I had a 400 litre tank I planned to use. Next, I read about the water conditions at Tasek Bera - being a Ramsar site, it was well-researched with lots of relevant publications available. Unfortunately, though, I quickly realised that I’d have to make some compromise. There was no way that I was going to be able to have a tank with acidic water when mine came out of the tap at 8.2 and all my tanks were consistently at 7.8, no matter what I did with them. I could, temporarily, nudge the pH down by adding driftwood, leaf litter and peat, but after a few water changes it always ended up back at 7.8.

On a more positive note, I also found a species list for the plants at Tasek Bera (Abdul Rahman et al. 2010). The list included all the trees and shrubs in the surrounding forest as well as aquatics - 807 species in total. Most of them I knew nothing about, but I did find a few familiar names on the list, including Limnophila (commonly known as ambulia), Ceratopteris thalictroides (narrow-leaved Indian fern), Barclaya and Cryptocoryne. The species of Cryptocoryne at Tasek Bera, C. purpurea, is not available in New Zealand to my knowledge, but I decided that if I had the right genus I would be happy. Having done the research, I was finally ready to set up the tank. Since I was going to have some rooted plants, I used Dalton’s aquatic mix capped with sand, plenty of driftwood and then leaf litter collected at various locations. I was able to find leaves of some trees that were the same genus as trees growing at Tasek Bera, such as the native hīnau (Elaeocarpus dentatus) and taraire (Beilschmedia taraire). I mostly used leaf litter from native forest, and I was careful to avoid anything toxic. The first residents in the tank were my pair of pearl gouramis – and they hated it. They were obviously stressed at being moved from the tank they had been in and spent most of their time hiding. However, once I added a group of the emerald eye rasboras they became much more confident. The emerald eye rasboras were obviously at home right from the start and within a few weeks I observed spawning behaviour from them.

Melanie Newfield

References:

Abdul Rahman, R.; Chew, M.Y.; Abdul Rahman, U.N.; Kamarudin, S. (2010). The flora of Tasik Bera, Pahang, Malaysia. Malayan Nature Journal 62. 249–306.

Fahmi-Ahmad, M.; Rizal, S.A.; Amirrudin, B.A (2015). Ichthyofaunal diversity of Tasek Bera Ramsar Site, Pahang, Peninsular Malaysia. Journal of Wildlife and Parks 30: 27–43.