Echinoderms

ghavutustarfish.jpg Johnsons_sea_cucumber.jpgSandDollar.jpg
external image thumbnail.aspx?q=1617318327213&id=21816036c03a7b56ab408fc60d9eeedf&url=http%3a%2f%2fwww.twodrinksminimum.com%2fwp-content%2fuploads%2f2010%2f11%2fsea-urchin.jpg

A. Organized Body Made of One or More Cells-Cheyanne C.

Echinoderms have a hard endoskeleton that is covered by a thin bumpy or spiny epidermis, and they have many cells.There spine is pointy and is a really good defense when another animal trys to attack them. They have a mouth, stomach, and intestines. They don't have a brain or head. They have Radial Symmetry which means that they have lines of symmetry going through a central point, and their bodies are arranged in a circular design. When one arm gets broken off than another one will grow back in place. There spine is pointy and is a really good defense when another animal trys to attack them.
echinoderm[1].jpg Body of an Echinoderm.

B. Obtain and Use Energy-Cheyanne C.

All echinoderms get their energy from eating food. The Sea Star is mainly carnivorous and uses its tube feet to open its prey's shell. Then it push its stomach through its mouth and into the prey. Sea stars eat animals that they can get to, mostly slow ones because they are slow. They eat dead animals sometimes. They also eat mollusks, mostly clams, and sea squirts, and sponges. The Sea Cucumber feeds on sediments on the sea floor. Sea Potatoes go through the sediment and pick up particles using their tube feet. Sea Lilies and the Feather Stars eat the tiny algae and other animals that make up plankton. They catch them with their pinnules which is an outreach, feathery arm.Sea Star feeds.

C. Reproduce-Emarie D.

All Echinoderms can reproduce sexually. Females produce the eggs, and males produce the sperm. To reproduce, females release their eggs into the water, which triggers the males to release their sperm. The sperm fertalizes the eggs The fertalized eggs then hatch into larvae. Few types of Echinoderms can reproduce asexually. To reproduce asexually the echinoderms have to split off parts off their bodies to from new individuals.
http://www.britannica.com/EBchecked/media/18513/Starfish-life-cycle-showing-the-release-of-eggs-and-sperm
Click on the link to see a video about starfish reproduction.

D. Grow and Develop-Will F.

The fertilized eggs of an Echinoderm develop and start out as larvae. They then live in their larvae form as free-swimming organisms with the plankton. When they are larvae they look very different from their parents. Then they grow into miniature adults before they go into the complete transformation into an adult. Once they are adults they mate sexually by putting eggs and sperm into the water. The sperm fertilizes the eggs then the life cycle repeats itself.
external image echinoderm_larvae.jpgLarva of an Echinodermexternal image thumbnail.aspx?q=1622217471383&id=fb7f83b8fb094c33784e31a4c1dccb9a&url=http%3a%2f%2fanimalstown.com%2fanimals%2fe%2fechinoderm%2fwallpapers%2fechinoderm-wallpaper-1.jpgGrown Echinoderm

E. Respond to Stimuli-Will F.

The Echinoderms don't have many ways to attack their enemies so most use defensive stratagies. The sea urchin doesn't move even close to fast enough to get away from predators so it has thin spikes that come out of its body to protect itself from them. The sea cucumber uses sticky threads that make the predator that is trying to eat them annoyed and make it find a different place to get their food. Predatory starfish are one of the only Echinoderms that hunt their prey. They only hunt the sea animals that are slower than themselves, like the bivalve mollusk. Once the starfish has a mollusk in its sight it sticks its mouth between the two halves and eats the mollusk alive.
external image 24MaySemakau5240033.jpgsticky threads of a sea cucumber

F. Exchange Gases with the Environment-Emarie D.

To exchange gases with the enviroment Echinoderms use their water vascular system. The water vascular system allows them to move, exchange carbon dioxide and oxygen, capture food, and release waste. The water vascular system is a network of water-filled canals with thousands of tube feet connected to it. Tube feet are hollow, thin-walled tubes that each end in a suction cup. Tube feet allow the Echinoderms to move. ( right: shows a digram of the water vascular system)
(Below: shows the Echinoderm usings its water vascular system to move)WaterVascularSystem.jpg



















Resources:
1. National Geographic Society; Biggs, Alton, et al. Life Science. New York: Glencoe McGraw-Hill, 2002.

2. deeznutts300000. "sea star eatting silversides." Youtube.com. 28 Febuary, 2012. http://www.youtube.com/watch?v=JdNcyXuz46w&feature=player_embedded.

3. Svancara, Theresa. Sea Stars and Other Echinoderms. Chicago, IL: World Book, Inc, 2002.

4. Gilpin, Daniel. Starfish, Urchins & Other Echinoderms. Minneapolis, MN: Compass Point Books, 2006

5. swangpol. "Starfish Locomotion." YouTube. Oct. 30, 2010. Feb. 28, 2012
< http://www.youtube.com/watch?v=HPhAGyDceLo&feature=player_embedded >

6.
reproduction: starfish life cycle. Video. Encyclopædia Britannica Online. Web. 28 Feb. 2012.
<http://www.britannica.com/EBchecked/media/18513/Starfish-life-cycle-showing-the-release-of-eggs-and-sperm>.