(phylum echinodermata)...(phylum echinodermata) april 08, 2013 examples of echinoderms sea cucumbers...
TRANSCRIPT
April 08, 2013
Echinoderms(Phylum Echinodermata)
April 08, 2013
Examples of Echinoderms
Sea cucumbersSea stars
Sea urchinsSand dollars
April 08, 2013
Echinoderms are...
Invertebrates with an internal skeleton, have radial symmetry, and a system of fluid-filled tubes
called a water vascular system
ALL echinoderms live in SALT water
April 08, 2013
Body Structure
Endoskeleton is an internal skeleton that is made of hardened plates
Bumpy texture
Radial symmetry - the body parts (usually in multiples of 5) are arranged like wheel spokes
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Movement
Water vascular system - internal system of fluid-filled tubes
Some of the tubes in this system can squeeze together and force water into the tube feet
The tube feet stick out from the side or underside of an echinoderm - the ends of the tube feet are sticky.
When the tube feet fill with water they act like suction cups the grip helps them move SLOWLY and capture food.
April 08, 2013
Reproduction & Life Cycle
- Almost all are either male or female- Eggs usually fertilized in the water- Female releases eggs / male releases sperm- Fertilized eggs develop into tiny larvae- Larvae look very different from adults- Undergo metamorphosis to become adults
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Four major groups of Echinoderms
Sea StarsBrittle StarsSea Urchins
Sea Cucumbers
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Sea Stars
- Predators that eat mollusks, crabs and other echinoderms- Use tube feet to move & capture prey- Can grasp prey with five arms- Release digestive chemicals to break down prey- Sucks partially digested food in through mouth
http://www.youtube.com/watch?v=A100m5EpfFI
April 08, 2013
Brittle Stars
- Arms are long and slender with flexible joints- tube feet have no suction cups- tube feet are used for catching food only- slither along the ocean bottom by waving their arms in a snakelike motion
http://www.youtube.com/watch?v=WOkppGxqcrM
April 08, 2013
Sea Urchins- Have no arms- Body is covered and protected by moveable spines- Look like a pincushion- Spines cover a central shell that is made of plates joined together- Use tube feet to move- Scrape and cut food (like seaweed) with 5 teeth-like structures that come out of their mouths
http://www.youtube.com/watch?v=D3W4OCnHyCs
April 08, 2013
Sea Cucumbers
- can be red, brown, blue or green- leather-like skin- bodies are soft, flexible, and muscular- have rows of tube feet on underside- crawl slowly along the ocean floor- have a mouth surrounded by tentacles, can lengthen tentacles to sweep food towards mouth- filter feeders
April 08, 2013