Transcript Echinoderms
Phylum Echinodermata Spiny Skinned animals Echinoderms– echin (spiny) and derma (skin) GENERAL INFORMATION Symmetry Secondary Pentaradial Symmetry– the larvae are bilateral and the adults are radial Body Development • Bilateral larvae • Pentaradial adult. Videos: http://www.youtube.com/watch?v=A100m5EpfFI starfish eating http://www.youtube.com/watch?v=6IP_I6IVyJQ&feature=relat ed starfish http://www.youtube.com/watch?v=E1t-Dz4u4u0 brittle star moving Water Vascular System Tube feet: used for feeding, moving, breathing, and even reproduction are extended by taking in water http://www.youtube.com/watch?v=4IRFpKVtuU tube feet The white parts are where the tube feet were in this sea urchin (Sea Stars) • • • • • Mostly eat clams and oysters or other animal that is too slow to defend itself It slowly pries open its prey in order to eat it, sending out its stomach to consume the body of the shellfish They have two stomachs—one is used to eat and the other is used for digestion Unlike the brittle star, sea stars’ organs enter their arms. They can break off their arms and the arms can regenerate (Sea Cucumber) • • • • • • Sea cucumbers are scavengers, looking for food at the bottom of the ocean They usually live in tropical reefs If it is threatened, it will stiffen and a jet of water will shoot out of one end If they feel threatened, they can also throw out their internal organs (evisceration) to distract predators, then grow new internal organs Delicacy to eat in some countries They use their tube feet to move very slowly • sea cucumber evisceration http://www.youtube.com/watch?v=a CxKFc3XtJs&NR=1 • Sea cucumber lifestyle • http://www.youtube.com/watch?v=vs LBOkYLLeI (Sea Urchin and Sand Dollars) http://www.youtube.com /watch?v=SRAfjvws13E sand dollar moving • • • Sand dollars become bleached and http://www.youtube.c loose their spines when left out in om/watch?v=4IRFthe sun on the beach, so the ones in the store are very different from pKVtuU tube feet live ones Sea urchins have teeth made of calcium carbonate, and the entire chewing organ is called Aristotle's Lantern Sea urchins mainly eat algae, but can also eat other invertebrates like mussels, sponges, and brittle stars Feather Star Sea Lily • Sea lilies were once thought to be planted in the ground but researchers found out that they actually can crawl from danger at 5 cm/s. They use their leg-like “petals” to crawl along the ocean floor. They use a lizard-like technique and leave their roots behind when escaping predators. http://www.umich.edu/news/index.html?Releases/2005/Oct05/crinoid Brittle stars • Long and nearly solid rays which move like snakes • Arms can regenerate • Carnivores, filter feeders, and scavengers • Coelem is smaller than other echinoderms