If you hang around a place like Punalu'u long enough, you really notice things. I've always enjoyed watching how the ocean interacts with the land, even when the tide is strong and the weather stormy.
Of course, crawling around on slippery lava rocks is easier to do when the sea is calm, and the weather is pleasant.
One afternoon, I saw these little round guys hanging out on the grassy rocks. About the size of baseballs, they didn't move around much, but the waves didn't knock them off their perches either. At first I thought they were mussels of some type.
Then I noticed how many little feet they had.
It turns out they are a type of sea urchin. Known as the Shingle Urchin or a Helmet Urchin, they don't have long, thin spines that could break easily in these intertidal areas. Instead, they have lots of flattened, tubelike feet, and what you can see on the outside, from above, is just a portion of them.
In other words, they've got many more underneath.
This gives them the ability to cling to whatever rock or surface they find, even when the weather is stormy, and the tide is strong.
Growing up, I always wanted to get picked first for games on the playground (instead of last). After years of trying to jog, run or play any team sports in school, I realized that Nature had blessed the folks with arches in their feet a competitive advantage. So I poured my energies into excelling in other areas.
Like me, the Shingle Urchins may not excel at team sports or dancing. But they're unique and notable in their own way, just like each of us.
Related Internet Links
Shingle Urchins at The Echinoblog