1. Echinoderms Shakila McKinney Ahkeen Aaron Jonathan Bailey

2. Biology of Echinoderms • Have radial symmetry which affects their lifestyle. They are sedentary slow bottom crawlers. • The nervous system coordinates movements of tube feet and spines in the absence of a brain. • In most groups, five, ten, or more gonads shed sperm or eggs directly into the water. So they are broadcast spawners. • Sea stars, brittle stars, and sea cucumbers are some of the echinoderms that use budding. • Then the two separate halves regenerate to become a whole.

3. Echinoderms: Five-Way Symmetry • Sea stars, sea urchins, sea cucumbers, and several other forms make up the echinoderms phylum. • Pentamerous: A symmetry based on five parts • Endoskeleton: A skeleton that is secreted within the tissues, rather than externally like the exoskeleton of arthropods. • Spines and pointed bumps give many echinoderms a spiny appearance and are nick-named “spiny-skinned” • Water Vascular System: A network of water-filled canals. • Tube Feet: Are muscular tensions extensions of these canals. • The tube feet help movement, attachment, locomotion, and for receiving chemical stimuli in marine life.

4. Types of Echinoderms • Sea Stars (class Asteroidea) • Brittle Stars (class Ophiuroidea) • Sea Urchins (class Echinoidea) • Sea Cucumbers (class Holothuroidea) • Crinoids (class Crinoidea)