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Echinoderms

Echinoderms. What are echinoderms?. spiny skin internal skeleton water vascular system tube feet. Form and Function. Water Vascular system Filled with fluid respiration Circulation movement Madreporite sieve like structure opening to outside. 5 part radial symmetry

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Echinoderms

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  1. Echinoderms

  2. What are echinoderms? • spiny skin • internal skeleton • water vascular system • tube feet

  3. Form and Function Water Vascular system • Filled with fluid • respiration • Circulation • movement • Madreporite • sieve like structure • opening to outside

  4. 5 part radial symmetry • bilaterally symmetrical • deuterostomes • blastopore develops into the anus

  5. Sea stars • Tube Feet • muscles pull up the center of the suction cup • Tube feet allow them to walk and pull open prey.

  6. Sea Urchins • use a 5 part jaw-like structure to scrape algae from rock

  7. Sea Lilies • use tube feet to capture floating plankton

  8. Sea Cucumbers • move like bulldozers taking in sand and detritus

  9. Sea Stars • feed on mollusks • Pry open shells • Push stomach out of its mouth • Secretes enzymes to digest mollusks in their own shells • Pulls stomach and partially digested prey back in

  10. Respiration and Circulation • surface respiration • tube feet • skin gills • water vascular system • carry oxygen, food and waste

  11. Excretion • Digestive waste • anus • Nitrogen-containing cellular waste • tube feet • skin gills

  12. Nervous System • not highly developed • nerve rings • Radial • Scattered sensory cells • detect • light • gravity • chemicals released by potential prey

  13. Movement • dependant on the type of endoskeleton • Most use tube feet with other forms of locomotion

  14. Sand Dollars and Sea Urchins movable spines

  15. Sea Stars and Brittle Stars have flexible joints

  16. Sea Cucumbers plates over a soft muscular body wall

  17. Reproduction • external fertilization • are either male or female • Sperm and eggs released into the water for fertilization • Larva have bilateral symmetry • develop radial symmetry

  18. Groups of Echinoderms

  19. Sea Urchins and Sand Dollars • Large solid plates around internal organs • Are detritivores • eat algae • Defense • burrowing in the sand (sand dollar) • wedging in rocks (sea urchins) • using sharp spines

  20. Brittle Stars • Common • especially on coral reefs • slender, flexible arms • rapidly escape predators • shed one or two arms • keep moving when • distract predators • Are filter feeders • detritivores • Nocturnal

  21. Sea Cucumbers • warty moving pickles • Are detritus feeders, • organic matter • remains of plants • remains of animals. • Roam across deep sea floor • herds of hundreds of thousands

  22. Sea Stars • creep slowly along the sea floor • carnivorous • prey on bivalves • pieces will grow into a new animal • Must contain a portion of the central body

  23. Sea Lilies and Feather Stars • oldest class of echinoderms • filter feeders • long feathery arms • Common in tropical oceans

  24. Sea lilies live attached to the ocean bottom by long, stem-like stalks

  25. Feather stars live on coral reefsand use their tube feet to catch plankton

  26. Ecology of Echinoderms • Sea urchins • help control algae and other marine life • Sea stars • predators to control the population of other organisms

  27. Crown-of-Thorns sea stars • threaten coral reefs • Have poisonous spines • Feeds almost exclusively on corals • destroyed extensive areas of the Great Barrier Reef in Australia

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