Sunflower Sea Star (Pycnopodia helianthoides) feeding upon Bryozoan (Heterapora pacifica) on stalks of Giant kelp (Macrocystis pyrifera), Breakwater, Monterrey, California.
The sunflower sea star (Pycnopodia helianthoides) is a large predatory sea star usually with 16-24 limbs called rays. It is the largest sea star in the world. Sunflower sea stars can grow to have an arm span of 1 m (3 ft.) in diameter. The color of the sunflower sea star ranges from bright orange, yellow and red to brown and sometimes to purple, with soft, velvet-textured bodies and 16-24 arms with powerful suckers. Most sea star species have a mesh-like skeleton that protects their internal organs. Easily stressed by predators such as large fish and other sea stars, they can shed arms to escape, which will grow back within a few weeks. They are part of the diet of the king crab.
Sunflower sea stars reproduce sexually and asexually. They also have separate sexes. Sunflower stars breed from May through June. In preparing to spawn, they arch up using a dozen or so arms to hoist its fleshy central mass free of the seafloor and release gametes into the water for external fertilization. The microscopic sea star larvae float and feed near the surface for two to ten weeks. After the larval period, the larva settles to the bottom developing as a planktonic form and transforming into a juvenile sunflower sea star, Juvenile sunflower stars begin life with five arms, and grow the rest as they mature. The life span of most sea stars is 3–5 years.