Sea urchins are really quite awesome.
The California purple urchin (Strongylocentrotus purpuratus)
Not only do they look really cool, but they are our closest invertebrate relatives on the ol’ evolutionary tree, genetically speaking. Good thing too, now that the entire genome has been coded for humans and sea urchins. This revealed that sea urchins are actually more closely related to us genetically than fruit flies.
Professors Gary Wessel and Sorin Istrail at Brown University plan to use this information in research on Huntington’s disease and muscular dystrophy.
They found a few surprises along the way, too. Apparently, sea urchins have a very sophisticated innate immune system. They also have genes associated with taste and smell, hearing and balance. They even have a robust gene set for visual perception…on their feet!
“I’ve been looking at these organisms for 31 years – and now I know they were looking back at me.” says Gary Wessel.
These echinoderms live on rocks and shells in the saltwater of low-tide to deeper water (up to 750 feet) areas. They mostly eat green algae, and move around on their small tube feet.
See also: Braccini, S. 2001. "Arbacia punctulata" (On-line), Animal Diversity Web. Accessed February 20, 2010 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Arbacia_punctulata.html.