1. Echinoderms Sam & Jen

2. Examples of Subgroups Crinoidea –Sea Lillies Asteroidea –Sea Stars Ophiuroidea –Brittle stars Echinodea –Sea Urchins & Sand Dollars Holothuoidea –Sea Cucumbers Blastoidea –Blastoids Star Fish Sea Lilly Sea Urchin

3. Body Systems Circulatory –none Excretory –Diffusion through tube feet, anus, or skin gills(no kidneys) Nervous –Nerve ring(circles mouth) & radial nerve(from nerve ring down each are) Reproductive –External Fertilization Sperm and eggs released into water –Asexual (regeneration) Can lose a ray to escape from predators and regrow it Tube Feet

4. Characteristics Multicellular w/o cell walls Heterotroph –Mouths located on oral(underside) of body Pentaradial Symmetry –5 rays(arms) branching from central body Deuterostome –Anus develops then mouth

5. More characteristics Pedicellariae –Tiny, jaw-like pinchers on skin Protection & self cleaning Dermal Endoskeleton –Hard, spiny or bumpy –Made of calcium carbonate plates Called ossicles

6. Water Vascular System Hydraulic system that operates under water pressure –Allows for movement, gas exchange, capture of food, excretion –Parts: Tube feet & Ampullae –Water enters through madreporite Acts as filter

7. Water Vascular System

8. Body Cavity True Coelom(body cavity) –Fluid inside bathes organs –Distributes nutrients & oxygen Sea Cucumber Brittle Stars