Like other sea stars, purple sunstars have an open circulatory system located within its body cavity, consisting of a central ring and five radial vessels that wrap around the inside of the organism. These vessels deliver nutrient and oxygen rich blood to various pores located throughout the sun star. Once the blood reaches these pores, it begins to seep into the tissues that make up the purple sunstar. Albeit, this process occurs pretty slowly, as an open circulatory system functions without much aide from surrounding muscle tissue.