Parasitic, amoeboid dinoflagellates.

SEXUAL reproduction has so far been unknown among the Dinococcales, unicellular brown algae belonging to the Dinophyceae (dinoflagellates). As we report here, however, the life cycles of two members of this group, Stylodinium sphaera and Cystodinedria inermis, include a parasitic amoeboid stage which brings about vegetative reproduction and also possibly sexual reproduction. We believe that the two amoeboid forms have previously been identified mistakenly as a separate taxon of protozoon.