Phylum Echinodermata.
<P>
   Echinoderms are spiny-skinned animals.
<P>
<BR><LI> class Asteroidea
<BR><LI> class Ophiuroidea
<BR><LI> class Echinoidea
<BR><LI> class Crinoidea
<BR><LI> class Holothuroidea
<BR><LI> class Concentricycloidea
<P>
   These deuterostomes reproduce by external fertilization.
<P>
   Sea urchin spawning:  <A ClAsS=MID Href="../../../med/Vid/Johnson4e/Wmv/Sea_Urchin_Reproduction.wmv" oNClick="popurlt('../../../../med/Vid/Johnson4e/Wmv/Sea_Urchin_Reproduction.wmv');txtcolor('phylum_Echinodermata8','gray');return false;" Id=phylum_Echinodermata8><iMg sRc="/images/wmplayer.gif" aLt='' boRDer=0></A>