Gourt > Science > Biology > Developmental Biology > Model Organisms > Sea Urchin
Sea urchins are spiny sea creatures of the class Echinoidea found in oceans all over the world. (The name comes from their resemblance to hedgehogs, hedgehog being one meaning of the word "urchin"). Their shell, which biologists call the test, is globular in shape, and covered with spines. The size of the test in adults is typically in the range of 3 to 10 cm (1-4 in.).
Typical sea urchins have spines 1-2 cm (approximately 1/2 to 1 in.) in length (e.g. "Sea urchin", right), a millimeter or two thick, and not terribly sharp. Diadema antillarum, familiar in the Caribbean, has thin spines that can be 10-20 cm long (4-8 in.). Common colors include black and dull shades of green, olive, brown, purple, and red.
Sea urchins are echinoderms (phylum Echinodermata), which also includes starfish, sea cucumbers, Brittle-stars, and crinoids. Like other echinoderms they have five-fold symmetry (called pentamerism) and move by means of hundreds of tiny, transparent, adhesive "tube feet". The pentamerous symmetry is not obvious at a casual glance, but is easily seen in the dried shell of the urchin (see picture below, right).
More on [ Sea urchin ]
Sea Urchin's body acts like a giant eye, scientists discover : Sea Urchin's body acts like a giant eye, scientists discover Sea urchins..
UnderwaterAsia (Underwater Asia) Thu, 07 Jan 2010 09:41:18 -0000
Sea Urchin's body acts like a giant eye, scientists discover : Sea Urchin's body acts like a giant eye, scientists discover Sea urchins..
@eliroth is this beard a side effect from the sea urchin debacle?
noise000 (this is a glitch) Thu, 07 Jan 2010 07:21:35 -0000
@eliroth is this beard a side effect from the sea urchin debacle?
DAMN I had some good sea urchin tonight. Daaaaaaaamn!
jeffrey (Jeffrey Kalmikoff) Thu, 07 Jan 2010 05:49:09 -0000
DAMN I had some good sea urchin tonight. Daaaaaaaamn!
was happy to see @eliroth on the Peoples' Choice Awards, but was sad to see that his walk was an uncomfortable, sea urchin induced hobble.
ravendies (Raven Dies) Thu, 07 Jan 2010 04:11:16 -0000
was happy to see @eliroth on the Peoples' Choice Awards, but was sad to see that his walk was an uncomfortable, sea urchin induced hobble.
@eserei27 @SkyeD awwww brave bear bear Jew. Sea urchin needled feet n all. I'm sure I can prob arhhhhhh a download fr smwhr lol
syzzlyn (Island Diva) Thu, 07 Jan 2010 04:05:02 -0000
@eserei27 @SkyeD awwww brave bear bear Jew. Sea urchin needled feet n all. I'm sure I can prob arhhhhhh a download fr smwhr lol
Dungenes crab soup, sea urchin and pea shoots. http://twitpic.com/x051r
kcarter80 (Keith Carter) Thu, 07 Jan 2010 03:31:30 -0000
Dungenes crab soup, sea urchin and pea shoots. http://twitpic.com/x051r
Sea Urchin Embryology - Glossary and illustration of the path of development, as resource to high schools, provided by Stanford University, California.
Meta Description: [ This is a site devoted to the interaction of a leading lab at Stanford University, under Dr. David Epel, with high school science teachers. ]
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