Rapid-flowing rivers in Asia
Mountain rivers in Asia: cold, oxygen-rich, with extremely strong currents. Habitat of hillstream loaches and other river fish.
Description
The mountain rivers of Southeast Asia (Vietnam, Laos, Myanmar, and western India) have characteristics that are the opposite of those of Amazonian rivers: cold, highly oxygenated water; a torrential current; and a smooth, rocky substrate covered with a biofilm. The fish and invertebrates are adapted to cling to the rocks.
Parameters
| Parameter | Value |
|---|---|
| pH | 6.5 – 7.5 |
| GH | 5–15 °dGH |
| Temperature | 18 – 24°C |
| O₂ | Saturated (> 8 mg/L) |
| Current | Very high (3–5 vol/hour) |
Aquarium Requirements
- Temperature: Without a heater or with a cooler — maximum 24°C
- Water flow: High-powered Powerhead or Koralia. "Racetrack"-style aquarium (long and narrow)
- Oxygenation: High — the flow creates sufficient turbulence
- Substrate: Smooth, flat river rocks (pebbles) + fine gravel sand between them
- Biofilm: Important for feeding — let the rocks become covered with a green film of algae
Representative species
| Species | Features |
|---|---|
| Sewellia lineolata (Hillstream) | Flat body with a suction cup; nothing on the rock |
| Gastromyzon punctulatus | Borneo Hillstream |
| Beaufortia leveretti | Hillstream from China |
| Homaloptera zollingeri | Elongated Hillstream |
| Danio choprai | Burmese Danio — vibrant colors |
| Danio kyathit | Blue-orange danio |
| Crossocheilus siamensis (SAE) | Eats seaweed; strong current |
| Garra flavatra | Rock cleaner; Burma |
| Puntius titteya (cherry barb) | Low and fast; with vegetation along the banks |
Decor
- Bedrock: flat, smooth river pebbles
- Coarse gravel among rocks
- No prominent trees (rocky rivers)
- No tall plants—just algae on rocks + maybe Microsorum attached to rocks
- Crystal-clear water (colorless)