Echino = “spiny” Dermis = “skin”
Some different echinoderms
Unifying Characteristics Spiny Skin Internal Skeleton – “endoskeleton” Water vascular system Muscular tube feet (suction cup feet) Pentaradia Symmetry 5 rays of symmetry
Water Vascular System Madreporite - sieve-like opening to the water vascular system
Water Vascular System Functions: Respiration Circulation Movement Ring & Radial Canals Tube Feet Circulation Movement
Tube Feet Each tube foot is basically a suction cup, muscles pull up the centre of the cup causing suction Many feet working together can exert huge force, allowing “walking” and attacking
Groups of Echinoderms Sea Urchins and Sand Dollars Brittle Stars Grazers and Detrivores Solid plates protect internal organs Brittle Stars Filter feeders and Detrivores Slender/Flexible arms – detach and distract Sea Cucumbers Detrivores Eviscerate themselves as defence! Sea Stars Predatory Regenerative if dismembered! Sea Lilies and Feather Stars Filter Feeders Feather dusters of the sea
Sea Urchins and Sand Dollars Grazers and Detrivores Solid plates protect internal organs
Brittle Stars Filter feeders and Detrivores Slender/Flexible arms – detach and distract
Sea Cucumbers Detrivores Eviscerate themselves as defence!
Sea Stars Predatory Regenerate if dismembered!
Sea Lilies and Feather Stars Filter Feeders Feather dusters of the sea