Amazonian fish are a diverse group of fish that are native to the Amazon River and its tributaries in South America. These fish are popular among aquarium enthusiasts due to their unique colors, patterns, and behaviors. Many Amazonian fish are also relatively hardy, making them suitable for beginner aquarists.

There are several popular Amazonian fish species that are commonly kept in aquariums, including the following:

1. Angelfish: These fish are named for their tall, triangular fins, which resemble the wings of an angel. Angelfish are native to the Amazon River and its tributaries, and are popular for their striking colors and patterns. There are several different species of angelfish, including the Zebra Angelfish, which has black and white stripes, and the Gold Angelfish, which has a metallic gold color.
2. Discus: These fish are native to the Amazon River and are known for their round, disc-shaped bodies and vibrant colors. Discus are often kept in community tanks with other peaceful fish, and they prefer a well-planted tank with plenty of hiding places.
3. Tetras: Tetras are small, schooling fish that are native to the Amazon River and its tributaries. They are known for their bright colors and active swimming behavior. Popular tetra species for aquariums include the Neon Tetra, which has a bright blue stripe on its sides, and the Cardinal Tetra, which has a bright red stripe on its sides.
4. Piranhas: These fish are native to the Amazon River and are known for their sharp teeth and aggressive behavior. While piranhas are often portrayed as ferocious predators in movies and television, they can actually be kept in a well-maintained aquarium with the proper care.

When setting up an aquarium for Amazonian fish, it is important to research the specific needs of the species you are planning to keep. Some Amazonian fish require a larger tank with a strong filtration system, while others can thrive in a smaller tank. It is also important to provide a varied diet for your Amazonian fish, including live or frozen foods such as worms, brine shrimp, and blood worms, as well as a high-quality pellet or flake food.

Overall, Amazonian fish can be a beautiful and rewarding addition to any aquarium. With proper research and care, these fish can thrive and bring a touch of the Amazon rain forest to your home.