Angelfish are a diverse group of freshwater and saltwater fish, but they share a characteristic laterally compressed, disc-shaped body and long, flowing dorsal and anal fins. Freshwater angelfish (\(Pterophyllumscalare\)) are often silver with dark stripes, are smaller (around 6 inches/15 cm), and are native to South American rivers. Marine angelfish (family Pomacanthidae), found in tropical reefs, can be much larger (up to 18 inches/46 cm) and come in a wide variety of bright, vivid colors.