Tetra is a type of fish commonly found in home aquariums. It is a small, colorful fish that is easy to care for and can live in a variety of water conditions. The name Tetra comes from the Greek word for four, referring to the four spines on its back. Tank fish are a popular choice for home aquariums because they are relatively easy to care for and can live in a variety of water conditions. They are also known for their bright colors and active behavior.