Discus Fish and Pterophyllum scalare in an Extra large fish tank, a large school of Firehead Tetras, Piecos and Coridoras. Many fish habitats in the Amazon are subject to fluctuations in the water level. Many of the rivers in the forest flood during the rainy season, sometimes over kilometers. During this time Neon Tetras, Discus fish and Freshwater Angelfish swim between the trees in water up to 15 meters deep. due to the flooding, water plants are rarely found in these areas.