Sunflower Seastar (40)
|I took this picture at the Seymour Marine Discovery Center at Long Marine Lab in Santa Cruz, California.|
An array of 24 arms distinguishes this magnificent sunflower star from other sea stars. Soft skin in colors ranging from purple to brown, orange or yellow adds to its beauty.
For a sea star, this animal is a voracious predator. When on the prowl for food, the sunflower star swings along on its 15,000 tube feet—moving at the remarkable speed, for a sea star, of over 40 inches (1 m) per minute.
The sunstar's prey use a variety of escape tactics to avoid being trapped by the Pycnopodia’s tube feet. Snails and abalones violently twist their shells to loosen the star’s powerful grip; cockles lower their strong foot and pole-vault away; California sea cucumbers, usually sedentary, slither out of the way; and sea urchins flee. Both red and purple sea urchins deploy their pedicellariae (pinchers) to nibble on the star’s tube feet. The purple urchin seldom escapes, however the red sea urchin has another defense—long spines, which usually ensure its escape.
Diet: crabs, sea cucumbers, snails, chitons, sea urchins, dead or dying squid and other sea stars
Size: to 39 inches (1 m) from armtip to armtip
Range: low intertidal and subtidal zones from Alaska to San Diego
Relatives: other sea stars, brittle stars, urchins, sand dollars, sea cucumbers; Phylum: Echinodermata
Juvenile sunflower stars start life with five arms—by maturity they sport up to 24 arms.
Most sea stars have a one-piece, semirigid skeleton. However, the sunflower star’s skeleton has a few disconnected pieces. They allow the sunstar's mouth to open wide and its body to enlarge and take in big prey. A sunflower star can swallow an entire sea urchin, digest it internally and then expel the urchin’s test—its external shell.
In Monterey Bay, the sunflower star eats—in season—dead or dying squid. After the star digests the squid, the indigestible squid pen—its internal shell, which is too large to be defecated—works its way through the body wall.