Identified as Prorocentrum gambierdiscus by original source; identified as Diplopsalis or Zygabikodinium by Dean Jacobson.

Coloured scanning electron micrograph (SEM) of the dinoflagellate, Prorocentrum gambierdiscus. Prorocentrum species produce okadaic acid, which is associated with diarrheic shellfish poisoning (DSP). Dinoflagellates are unicellular protozoans. About 90% are found in marine environments as plankton. They are characterised by the presence of two flagella (not visible). One flagellum beats back and forth, while the other is flat and ribbon- like, and works as a rudder to steer and rotate the organism. (via)