About the biotope
I've tried a blackwater biotope once during my time as an aquarist, and I'm sure many others have too. These biotopes aren't just one type, they vary based on geographical location. Tropical rainforests in Asia and South America are home to most blackwater habitats, which get their name from the brownish tint caused by tannins.
Asian blackwater habitats
In Southeast Asia, you'll find many blackwater habitats, with Indonesia, Thailand, and Borneo being some of the main locations. These habitats differ from their South American counterparts in terms of plants and livestock. Some rare fish thrive in these habitats, like the ones found in peat swamps with small cyprinids and wild bettas. Plants like crypts and Bucephalandra are native to these areas and can handle the conditions. The North Salangor peat swamp area is home to 48 species of fish, with 6 being endemic to the area. The endangered Betta albimarginata is found in the Indonesian province of Kalimantan Timur, in the Sebuku River. They live in shallow blackwater swamps, about 5-10cm deep, among roots and leaf litter. We don't know much about the species' threats, as its biology and threats remain relatively unknown. It's a mouthbrooding fish, which means raising fry from the mouth area. They're excellent jumpers, so a tank lid is a must to prevent escape.
Betta albimarginata
South American blackwater habitats
These are the most common type of blackwater habitats to replicate. They're mainly found in blackwater rivers and basins in the Amazon Rainforest and surrounding areas, like Rio Negro and Rio Orinoco. I've kept cardinal tetras for about 7 months, and I'm planning to move them to a bigger tank to reduce stress. They're endemic to the upper Negro and Orinoco rivers in Brazil and Colombia, and reach a size of 3-5cm. They're popular in the aquarium trade due to their colourful bodies. Plants from the Rio Negro area include Hygrophila and Hemianthus, while those from the Rio Orinoco area include Cabomba and Echinodorus.
A cardinal tetra
How to build a blackwater biotope
Building a blackwater aquarium is relatively simple. You'll need leaf litter, which should be boiled before adding it to the tank. Mix river sand with small gravel to create a riverbed effect. Driftwood is also important, as it releases tannins like leaf litter. Add native plants that can handle the conditions, and remember to place the larger plants in the background first to create depth.
Conservation of blackwater habitats
These habitats are becoming increasingly rare and may disappear in the near future if we don't act. One way to conserve them is by recreating their habitats in a large home fish tank or preserving national parks that have them. Public aquaria displaying these habitats are rare, so it's essential to talk to your local aquarium about them. No public aquarium in Australia has a blackwater habitat on display. Education about blackwater ecosystems is crucial, and creating a blackwater tank in a school can be a great way to teach kids about biology and ecosystems.
Who Gives A Fish Forums
⇧
⇩