Saturday, July 31, 2010
July 31, 2010 : Sunflower Starfish
The sunflower starfish (Pycnopodia helianthoides) is a large predatory starfish usually with 16–24 limbs called rays. It is the largest starfish in the world. Sunflower starfish can grow to have an arm span of 1 meter (3 ft 3 in) in diameter. The color of the sunflower starfish 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 starfish species have a mesh-like skeleton that protects their internal organs. Easily stressed by predators such as large fish and other starfish, they can shed arms to escape, which will grow back within a few weeks. They are preyed upon by the king crab.
Sunflower starfish are quick, efficient hunters, moving at a speed of one meter per minute, using 15,000 tube feet which lie on the undersides of the body. They are commonly found around urchin barrens, as the sea urchin is a favorite food. They also eat clams, snails, abalone, sea cucumbers and other sea stars. In Monterey Bay, California, they will feed upon dead or dying squid. Although the sunflower sea star can greatly extend its mouth, for larger prey, the stomach can extend outside the mouth to digest prey, such as gastropods like abalone. Their feeding behavior was filmed for the BBC in the 2006 nature documentary Planet Earth and again in 2009 for Life.