Transcript Echinoderms
Kingdom: Animalia Phylum: Echinodermata 5 Classes: Asteroidea (Sea Stars) Crinoidea (Sea Lilies and Feather Stars) Ophueroidea (Brittle Stars) Echinoidea (Sea Urchins) Holothuroidea (Sea Cucumbers) 6,000 species Radial Symmetry (Adults) Bilateral symmetry (Larvae) Spiny skinned (where its name comes from) Tube feet Controlled by water vascular system Water-filled system of interconnected canals and tube feet (used to crawl along the sea floor, collect food, and respiration) No heart, brain, or eyes Globally distributed in almost every ocean depth Highest diversity in: Reef environments Shallow shores Deep ocean With the help of ocean currents larvae can swim great distances and this creates global distribution Asexual Echinoderms can regenerate missing limbs, arms, spines and even intestines (sea cucumber) Some brittle stars and sea stars can reproduce asexually by breaking a ray or arm, or by splitting the body in half (fission) Each half then becomes a whole new animal Sexual Release sperm and eggs into the water Most species produce pelagic (free floating) planktonic larvae Larvae are bilaterally symmetrical, unlike their parents When they settle to the bottom they change to the typical echinoderm features 1,600 species Radial symmetry (5 arms or more) Skeleton: ossicles Small calcareous plates that move with one another forming flexible joints Live on coral reefs, sand, and rocks Most are carnivorous and scavengers They eat clams, oysters, coral, fish, and other animals Stomach extrudes over prey, digestive juices are secreted and the tissue of the prey is liquefied Tube feet are important Locomotion Food collection Respiration Sea lilies 80 living species Sessile (attached to the ocean floor) Feather Stars 520 living species Not fully sessile Can crawl along the surface and swim short distances Unique because of mouth/anus on upper surface Filter feeders (eat whatever they find floating by) Feeding: pinnules wraps prey in mucous secretions, and ciliary tracts on the groove floor then transport it toward the mouth Feed on plankton (that’s why they like habitats with strong currents) 2,000 species Most active and fastest moving Long slender arms (similar in looks to sea star) Skeleton: ossicles Scavengers and detritus feeders Used for locomotion (not dependant on tube feet) Feed on small crustaceans, plankton or worms No anus (just digestion) they push out their stomachs to eat food like the sea star does 900 living species Spine covered (used for protection, and some are poisonous) lack distinct arms Hard skeleton: ossicles are fused (known as “test”) Eat using Aristotle’s Lantern (located in mouth on underside of their body, waste is sent out the anus at the top) 5 teeth Used to pull and rip algae off rocks Herbivores Seaweed Algae Bits of plants and animals 1,500 species Soft bodies, tough and leathery skin Skeleton: ossicles have degenerated and buried in fleshy body Mouth is surrounded by several tube feet that have been modified into tentacles that capture small organisms they eat When threatened they can throw up their insides and grow new ones back Filter feeder Feed on plankton http://en.wikipedia.org/wiki/Echinoderm http://www.bio200.buffalo.edu/labs/echinoderm s.html http://www.starfish.ch/reef/echinoderms.html http://www.oceaninn.com/guides/echino.htm http://tolweb.org/Asteroidea http://www.allthesea.com/Sea-Cucumbers.html http://library.thinkquest.org/J001418/urchin.htm l http://tolweb.org/Echinodermata http://library.thinkquest.org/26153/marine/ench ino.htm