Discus fish. Photo credit: Emily Etherington.
The discus fish are a genus of cichlid freshwater fish native to the Amazon River basin; three different species are known. Discus fish have a laterally compressed body and a rounded shape due to their lack of extended fins. The sides of the fish are frequently patterned in shades of green, red, brown, and blue. The height and length of the grown fish are both about 20–25 centimeters (8–10 inches)