Echinodermata

Phylum Echinodermata

General characteristics: Deuterostomes Water Vascular System Pentaradial Symmetry in most Nervous system lacks a distinct brain, but has radial nerves and circumoral ring Complete digestive system in most Respiration by various structures depending on class (papulae, tube feet, respiratory trees, bursae) Endoskeleton of calcareuos plates (ossicles) covered by epidermis

Phylogeny Class Asteroidea Class Ophiuroidea Class Crinoidea Class Echinoidea Class Holothuroidea