Wednesday, March 10, 2010

Echinoderms

This week we were learning about Echinoderms in our Marine Biology Class. Echinoderms are 'spiny skin' creatures. The classic Echinoderm joke:
How did the Sea Cucumber and Sun Star pay for their lunch?
They used a Sand Dollar.

Taylor was really excited about this sea cucumber because it had a limpet attached to it and a small barnacle attached to the limpet! Also you can see the radial pattern of 5. The sea cucumber has 5 rows of tube feet that it uses to crawl along the sea floor. The cucumber has an interesting line of defense, if it is threatened it spits out its guts. The sticky internal organs glue a predators gills or throat shut! Then the cucumber regenerates its internal organs. The 5 pattern corresponds to the five arms of a sea star and the five rows of tube feet on a sea urchin and the 5 petal pattern on the sand dollar.

This sun sea star has 15 legs! Again, using the pattern of 5. You can see the sea star's mouth at the center of the central disk. The sea star's stomach will leave the mouth and engulf it's prey. Once it has done that, it immediately begins digesting the animal, then, as the food gets mushier, the sea star pulls the stomach back in through the hole to be fully digested.


At our local marine life center, they have a tank that you can 'go inside'. Actually it is better than that because you don't even have to get wet! We got to see an anemone attached on the bubble and a limpet. Liberty loved all the sea life!

We tried really hard to find the eyes on the ends of the rays of the sea stars, next time we will have to bring our magnifying glass.
We did see the Aristotle's lantern on the sea urchin. The Aristotle's lantern is the 5 special teeth
an urchin uses to scrape algae off rocks and bore holes in rocks for them to have a place to hide.


The Marine Life Center has great volunteers and are willing to spend a lot of time answering questions an showing us what we are looking for and teaching us more! We were not disappointed!

One of the highlights today were the shrimp! The children were shown how to catch them and were all successful at it!



I decided that as a treat we would enjoy some local shrimp at The Shrimp Shack. Not the type of place I would normally take all of my children for lunch, because of the cost. Fortunately, I had packed lunch so they should not have been starving and we all shared a platter of beer battered deep fried shrimp and chips!
They all wanted more than their allotted 2! It was fun memories made.



We came home and are attempting to make our own echinoderms using a saturated salt water solution and cotton thread. Taylor's solution is the purple one, and she wanted to make sure that her solution was really saturated! Good thing I buy salt in bulk, I think they each used about 3 Cups of salt. Hopefully they are not too saturated and it will work, I will keep you posted.

4 comments:

Jodi said...

Hi Carolyn! I love that you post these FUN things you guys are doing for school. It inspires lots of good ideas for me. :) It looks like you guys have lots of fun together!

Theresa said...

Excellent!!!!You guys saw some really neat stuff! And how nice to top it off with shrimp for lunch!Yay!

Kelly C said...

When we lived overseas, some of our national friends took us out to a special dinner that included sea cucumber. They were very excited and proud to offer us such a delicacy. To date, it is still the single food item I have never managed to actually swallow. It's much more fun to examine the outside than to eat it :-) What a great study!

Carolynn said...

Kelly, if you did not actually swallow it what exactly did you do with it? I does not sound like a delicacy to me!