The red cushion star (Oreaster reticulatus) is a species of starfish found in the western Atlantic Ocean and the Caribbean Sea. It is the largest starfish found within its range, growing as large as 20 inches (50 centimeters) in diameter. It usually has five thick, broad arms projecting from a broad cushioned disc but has been found with four, six and even seven. The upper surface is hard and is covered with blunt spines. It is found in a variety of colors including shades of red, orange, yellow, and brown and feeds primarily on sponges.