1. 1 Phylum Echinodermata Echinoderms are an ancient group of marine animals, with about 6000 living species -Characterized by deuterostome development and an endoskeleton

2. 2 Echinoderm Body Plan The echinoderm body plan undergoes a fundamental shift during development -Larvae = bilateral symmetry -Adults = pentaradial symmetry Body structure is discussed in reference to their mouths, which define the oral surface

3. 3 Echinoderm Body Plan Endoskeleton -Found internal to a delicate epidermis which contains thousands of neurosensory cells -Composed of either movable or fixed calcium-rich (calcite) plates called ossicles -Perforated by pores to allow extension tube feet -Contains mutable collagenous tissue -Provides ability to autotomize body parts

4. 4 Echinoderm Body Plan Water-vascular system -A hydraulic system that aids in movement and feeding -Composed of a central ring canal from which five radial canals extend into each of the body’s five parts -Madreporite = Opening for water entry -Ampulla = Muscular sac for tube feet control

5. 5 Echinoderm Body Plan

6. 6 Echinoderms have a large coelom which connects with a complicated tub system -Helps provide circulation and respiration through extensions called papulae

7. 7 Echinoderm Body Plan Reproduction -In some echinoderms, asexual reproduction takes place by splitting -Broken parts can regenerate the whole animal -Most reproduction in the phylum is sexual and external

8. 8 Classes of Echinoderms There are more than 20 extinct classes In addition, there are five extant classes 1. Crinoidea (sea lilies and feather stars) 2. Stelleroidea (sea stars) Asteroidea (sea stars) Ophiuroidea (brittle stars) 3. Concentricycloidea (sea daisies) 4. Echinoidea (sea urchins & sand dollars) 5. Holothuroidea (sea cucumbers)

9. 9 Classes of Echinoderms