Sunflower starfish

Taxobox
name = Sunflower Sea Star


image_caption =
regnum = Animalia
phylum = Echinodermata
classis = Asteroidea
ordo = Forcipulatida
familia = Asteriidae
genus = "Pycnopodia"
species = "P. helianthoides"
binomial = "Pycnopodia helianthoides"
species_authority = Brandt, 1835The sunflower sea star ("Pycnopodia helianthoides") is a large predatory starfish with 15-26 limbs called "rays". They can grow up to an arm span of 1 m (3 ft.) in diameter. [http://www.nmfs.noaa.gov/speciesid/fish_page/fish6a.html Sunflower sea star - NOAA] ] 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.Telnack, Jennifer. [http://www.nwmarinelife.com/htmlswimmers/p_helianthoides.html "Intertidal Marine Invertebrates of the South Puget Sound"] . NW Marine Life.] 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.

Feeding

The sunflower sea stars are quick, efficient hunters, moving at a speed up to three meters per minute, using 15,000 tube feet which lie on the undersides of the body. They commonly hang around urchin barrens, as the sea urchin is a favourite 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 bivalves like abalone. [http://www.ci.edmonds.wa.us/Discovery_programs_website/Sea_Stars_&_relatives.html "Sea stars and relatives"] Edmonds Discovery Programs, City of Edmonds, Washington.] Their feeding behavior was filmed in the 2006 BBC nature documentary, Planet Earth.

Reproduction

Sunflower sea stars 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 [http://www.mbayaq.org/efc/living_species/print.asp?inhab=497 "Monterey Bay Aquarium: Online Field Guide - Sunflower star"] . Monterey Bay Aquarium.] The life span of most sea stars is 3–5 years.

Habitat

Sunflower sea stars are common in the Pacific from Alaska to Southern California, and are largest in Puget Sound, British Columbia and Alaska. [http://www.boydski.com/diving/photos/Sunflowerstar.htm "Sunflowerstar"] . Scott Boyd's Emerald Sea Photography.] They generally inhabit low subtidal and intertidal areas rich in seaweed [http://www.humboldt.edu/~intertid/stars_urch/echinos.html "North Coast Intertidal Guide: Seastars & Urchins"] . North Coast Intertidal Guide. Humboldt State University. Arcata, CA.] or kelp. [http://www.nps.gov/chis/naturescience/sunflower-star.htm "Sunflower Star"] . Channel Islands National Park. National Park Service.] They do not venture into high- and mid-tide areas because the body structure is fleshy and requires water to support it. [http://northislandexplorer.com/echinoderms/sunflowerstar.htm "Sunflower Star"] . North Island Explorer.]

References

External links

*ITIS|taxon="Pycnopodia helianthoides"|ID=157274|date=9 April|year=2007
* [http://www.nmfs.noaa.gov/speciesid/fish_page/fish6a.html Sunflower sea star - NOAA]