Dinoflagellates.
<P>
   Spiral  flagella  lie in a groove around the cell, which is reinforced
   by internal plates of cellulose.
<P>
   Some  of  the  photosynthetic species can undergo explosive <A ClAsS=MIZ Href="../../..//med/red_tide.html" oNClick="popurlts('../../..//med/red_tide.html',558,580);txtcolor('dino1','gray');return false;" Id=dino1 ClAsS=MIZ>growth</A> and
   cause red tides.
<P>
   Their  toxins  can  accumulate  in  molluscs  and  result in shellfish
   poisoning.
<P>
   Dinoflagellate spinning:  <A ClAsS=MID Href="../../../med/Vid/Campbell7e/Dinoflagellate-V.swf" oNClick="popurlt('../../../../med/Vid/Campbell7e/Dinoflagellate-V.swf');txtcolor('dino2','gray');return false;" Id=dino2><iMg sRc="/images/shockwave.gif" aLt='' boRDer=0></A>