S: Chapter 11.5 Echinoderms
FC: Echinoderms Chapter 11.5 | By: Alejandra Guzman, Lauren Sutton, Daniel Leon and Alex Thurmond
1: Echinoderms are radially symmetrical invertebrates that live on the ocean floor. Echinoderms means spiny skinned. all echinoderms of the animals have spiny skin or endoskeletons that are made of plates containing calcium. The numbers of body parts that an echinoderm has is almost always a multiple of five. Some examples of echinoderms are: sea stars, sea urchins, sand dollars, and sea cucumbers.
2: wATER vASCULAR sYSTEM | eCHINODERMS HAVE fluid filled tubes inside their bodies. These system of tubes is called the water vascular system. echinoderms use this to fill their bodies with water. Some parts of the system can contract, and squeeze water into the echinoderms tube feet. The ends of tube feet are sticky and can act like suction cups when they are filled with water. Echinoderms have rows of tube feet under their body. They use these tube feet to move, stick to the surface, or capture their prey.
3: Reproduction | most echinoderms are male or female and reproduce sexually. The eggs are fertilized in the seawater, outside of the animals body, and after The female releases her eggs and the male releases his sperm. The eggs later turn into tiny larvae that can swim around, and eventually go through metamorphosis and become adults.
4: Sea Stars | sea stars eat crabs, mollusks, and other echinoderms. it uses its arms and tube feet to capture its food. Then it forces it own stomach through its mouth and uses digestive chemicals to break down its food. Then it sucks in its prey and is finished digested inside the body.
5: Sea stars | A sea star has the ability to go through a process known as regeneration. This means that if it loses one arm, it can grow it back. Other species of sea stars can even grow a whole animal from a single arm. This is HOW SOME species OF Sea stars REPRODUCE.
8: Brittle Stars are kind of like Sea Stars. They regenerate lost arms. But their tube feet don't have suction cups and the tube feet are used for catching prey.
9: Sea Urchins, like Sand Dollars, have no arms. They can move their spines that protect the bodies. They move around the ocean floor from their tube feet that extend from between the spines.