Counts of regular and altered morphs of P. brachykentron were performed with
an Olympus CK40 inverted microscope at 400 magnification using 2 mL
Utermöhl sedimentation chambers with an estimated error (α¼0.05). It was
considered altered morphs when cells had its margins with notches, an increased
dorsal–ventral thickness, and the presence of large paramylon bodies.