AN IMPROVED STRIPPING TECHNIQUE FOR LIGHTLY ARMORED DINOFLAGELLATES 1

Identification of armored heterotrophic dinoflagellates relies, in part, on plate tabulations obtained by SEM. Currently, two methods are used to visualize plate morphology and develop plate tabulations: swelling the sutures between the cellulose plates of intact organisms or stripping off the outer membranes with ethanol to expose the underlying cellulose plates. Both approaches are problematic with lightly armored dinoflagellates because sutures do not consistently swell to enable visualization, and the outer membranes are not consistently stripped. Further, generic and species differences necessitate frequent modification of these protocols to obtain reliable results. We describe an improved membrane stripping technique using the detergent Triton X‐100. Our method provides a more consistent standardized approach to removing the outer membranes of lightly armored dinoflagellates, including Pfiesteria shumwayae Glasgow & Burkholder, a taxon that has, until now, proven very difficult to strip with currently published methods. This method allows visualization of the sulcus, a region previously difficult to observe, and will greatly facilitate taxonomic studies of the lightly armored forms.