Vocabulary 0ssicle = protective spines on a sea star Ampulla = a bulb-like sac at the base of a tube foot that functions in movement Bipinnaria =free swimming larva

Vocabulary Pedicellariae = pincer-like structure that protects and cleans body surface Madreporite = sieve-like plate on the abdomen where water enters

General Characteristics A. Undergo Metamorphosis - Bipinnaria to bottom-dwelling adult B. Endoskeleton = internal skeleton C. Water Vascular System - aids in movement and feeding

General Characteristics D. Tube Feet = help with movement, feeding, respiration, excretion E. Nervous System - no head or brain F. Fossils - date back to Cambrian period (over 500 million years ago) G. Radial Symmetry

Reproduction A. Asexual = regeneration (if part of central disk is attached) B. Sexual = releases eggs from holes under arm; eggs form tiny swimming larvae; larvae settle on bottom & develops into sea star

Water Vascular System (network of canals where muscle contraction permits movement) A. Water enters sieve plate; passes through madreporite and down a canal B. Radial canals carry water to tube feet

Water Vascular System C. Muscles contracts forcing water into ampulla; creates suction; suckers grip surface D. Ampullae contracts; water enters feet, releasing grip and feet extend

Other Echinoderms A. Crinoidea “lily-like”= sea lilies and feather stars

Echinoderms B. Asteroidea “star-like” = starfish; live in coastal waters and rocky shores

Echinoderms C. 0phiuroide “snakelike” = largest class; basket stars and brittle stars

Echinoderms D. Echinoidea “hedgehog like” = sea urchins & sand dollars

Echinoderms E. Holothuroidea = soft bodies; armless sea cucumbers