Morphological variability of Ptychocylis obtusa

Morphological variability of Ptychocylis obtusa found in a single sample. The 18 cells shown were the first properly orientated cells encountered in a sample aliquots from Station 9 of the 2014 cruise. Certain individuals shown have lorica morphologies resembling those of forms recognized as distinct species of Ptychocylis: P. drygalski (C) and P. acuta (F & O).