Tetra << TEHT ruh >> is a type of small tropical fish that lives in rivers of South America and Africa. Tetras are also called characins. There are nearly 1,500 species of these fish. Tetras are popular aquarium fish because they can be raised in captivity and have beautiful colors. Most tetras grow 2 to 3 inches (5 to 8 centimeters) long and live 3 to 4 years.
Popular species for home aquariums include neon tetras, bleeding-heart tetras, cardinal tetras, and diamond tetras. The neon tetra has a brilliant blue stripe along the side of its body. The bleeding-heart tetra has a red splotch on the middle of its side. The cardinal tetra is deep red on the sides and the belly. The diamond tetra has a bright silver color.
