Pycnopodia helianthoides, commonly known as the sunflower seastar, is a large sea star found in the northeast Pacific. It is the largest sea star in the world, with a maximum armspan of 1 m (3.3 ft). Sunflower seastars usually have 16 to 24 limbs; their color can vary widely. They are predatory, feeding mostly on sea urchins, clams, snails, and other small invertebrates.