About Orthasterias koehleri (deLoriol, 1897)
Orthasterias koehleri, commonly called the rainbow star, is a large species of starfish. It grows to an overall diameter of about 50 centimetres (20 in), with an individual arm length of 21 centimetres (8.3 in). It typically has five slender, tapering arms. Its aboral (upper) surface is pink or red, marked with irregular patches or bands of darker red, orange, or grey. The entire surface is covered with sharp white or mauve spines, and each spine is surrounded by a ring of pedicellariae: tiny, pincer-like organs. This species is found in the northern Pacific Ocean, with a range that extends from California to Alaska. It occurs at depths down to about 250 metres (820 ft), and can also be found on mid-ocean knolls and seamounts. It is an uncommon species, and is most often found on soft mud or sand bottoms, or on kelp or rock surfaces.
