http://www.youtube.com/watch?v=Fo-gcZ78Ij0&mode=related&search=
Echinoderms The spiny misfits
General Characteristics Larvae have bilateral and adults have radial symmetry No head! Endoskeleton- calcium carbonate
Water vascular system Pattern of development in embryos is more similar to vertebrates
General Characteristics Number of arms is in multiples of 5 Separate sexes Nerve ring Open circulatory system Body cavity
Body Most are carnivorous with a complete digestive tract Nervous system is simple looking but these orgs have complex behavior Regeneration is highly developed
Network of water filled canals Water Vascular System Network of water filled canals Connects to the outside by a pore called the madreporite
Tube feet extend when filled with water thru canals Used for locomotion and attachment
CLASSES OF ECHINOS Asteroidea Echinoidea Holothuroidea Ophiuroidea Crinoidea
Slow moving, flexible arms Asteroidea- sea stars Slow moving, flexible arms Predators of bivalves, snails, barnacles (slow-moving or attached animals) Feed by everting stomach thru mouth http://www.youtube.com/watch?v=prCeHDa7GTQ
Echinoidea- sea urchins, sand dollars Round hard endoskeleton with movable spines Graze on sea weed and sea grasses as well as scavenge Aristotle’s lantern- special mouth and jaw parts http://www.youtube.com/watch?v=SRAfjvws13E http://www.youtube.com/watch?v=NdgyaRFgvQQ
Holothuroidea- sea cucumbers Worm like Deposit feeders Interesting defense mechanisms Secrete toxins Discharge mucus and toxins thru their anus Eviscerate guts thru mouth or anus (they’ll grow back) http://www.youtube.com/watch?v=lKWSLg5PDiU http://www.youtube.com/watch?v=vsLBOkYLLeI
Ophiuroidea- brittle stars Arms very flexible and can move quickly Deposit feeders Largest group of echinos but stay hidden http://www.youtube.com/watch?v=XV0KAr_M-7w&feature=related
Crinoidea- feather stars and sea lilies Suspension feeders with feathery arms for feeding Deep water and either attached to the bottom or crawl http://www.youtube.com/watch?v=affSVrHHDfk&mode=related&search= http://www.youtube.com/watch?v=m7X6q-dfslQ&mode=related&search=