to 16.1 cm, with the ratio between the length of the arm and the radius of its disc ranging from 3.6:1 to 5.9:1. It has five arms and a small central disk. It can be distinguished from similar species by the distinctive upturned tips of its arms. The underside is completely yellow. It shows a wide range of colours on its dorsal side: orange to yellow, sometimes red and purple. The arms are unevenly covered with small, jagged-edged spines, which line the groove in which the tube feet lie, and join up at the mouth in a fan-like shape. Similar species According to Verrill it most resembles the species Asterias forbesi and A. rubens from the north Atlantic. It is distinguished by its lack of interactinal plates and the evenly reticulated arrangement of the dorsal plates. Distribution Native It is native to the coastal seawaters of northern China, North and South Korea, far eastern Russia, Japan, the Aleutian Islands, Alaska (from the Bering Sea to the Gulf of Alaska) and Canada (British Columbia). It is found throughout the Sea of Japan. It is common within its native range. In Japan it is found on both coasts from Hokkaido to (northern) Kyushu and in the Seto Inland Sea: in Mitsu Bay off the coast of Yokohama, in Aomori Prefecture off the coast of Odanozawa and elsewhere, along the coast of Yamagata Prefecture, Tokyo Bay, between Tateishi and Ogashima in Sagami Bay off Nagai, off Hayama, in Karatsu Bay, Hakata Bay, Osaka Bay, Ise Bay, Sendai Bay and Ariake Bay. In South Korea it is found on both the Pacific and the Sea of Japan coasts and has been found in Dokdo, Geoje Island, Jangmok and Tongyeong. In Russia it is found in the Peter the Great Gulf in Primorsky Krai, in the Chukotka Autonomous Okrug in the eastern Chukchi Sea to the Arctic Ocean, Kamchatka, the Kuril Islands, both east and west shores of Strait of Tartary and on both coasts of Sakhalin. In Canada it was collected in 1887 northeast of Vancouver Island, British Columbia, although records from Canada and Alaska may represent accidental human introductions. Introduced This species has been introduced to oceanic areas of Tasmania in southern Australia, parts of Europe and Maine. It was first collected in 1982 and first reported in 1985 in the Derwent River estuary in Tasmania, and first reported in Victoria, Australia in