What is more pointy than a sea urchin? In addition to the spines that most people see, sea urchins have small pinchers in between their spines called pedicillaria. The pedicillaria are used to pinch off any creature which tries to settle on them (like barnacles or algae) for a free ride. They can also be used as a defense against predators who aren't deterred by the spines, like sea stars. The urchin will fold down their spines and use the pedicillaria to pinch the sea star's tube feet and stomach.
They also have super pointy teeth. There are five teeth that continuously grow and are held in a structure called Aristotle's lantern. They use these teeth to scrape algae off of rocks, and to form little pockets in the rock where they live. Sea urchins kept in aquariums can cause lots of damage to the acrylic by chewing it up, and if they are kept in a concrete and fiberglass touch tank, they can chew right through it.
9 comments:
I enjoyed your photos of (and information about) sea urchins today. Great choice for today’s theme! I shared earlier at Sacred Ruminations.
Hugs and blessings,
Cool! Thanks for the marine biology lesson too! :)
Mine's up!
http://tanjuakiohome.blogspot.com/2008/07/photohunt-pointed.html
looks like we both have two things in common... you and urchins :)
hey kiddo, will call you later this afternoon. Hoping you're having a good day :)
Great catch for today's theme... Mine's up too hope you can visit... Happy weekend.
wow, thanks for the photos & info!
happy photo hunting =)
All urchins have five teeth? That's interesting trivia. I wonder how I can use it....
When you mentioned pointy teeth, I could hear a line from Monty Python And The Holy Grail in which a character describes the attack rabbit as having pointy teeth. I don't think I will be having a sea urchin for a pet anything soon. :-)
I've got my PhotoHunt entry up at http://www.anniemayhem.com/cgi-bin/wordpress/ in case you're interested. If you do visit, please leave a comment and feel free to explore the rest of my little blog.
I learned something new on sea urchin today. Those teeth looks nasty!
Wow, who knew?!? Very interesting!
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