The Southeast Asia River Environment includes the larger rivers of mainland Asia, as well as those in the Malay Archipelago. These waters are fast moving, very high in oxygen, and grow rich in plant fauna. This niche is also a typical habitat for thin, fast moving, streamlined fish. Tan to light brown gravel mixed with white or tan sand is recommended to simulate the natural substrate. Large, round pebbles (which have been made smooth by the flowing water), driftwood, and plants should also be used to recreate this niche.