Phacus
Euglenoids usually reproduce asexually by dividing longitudinally from apex to base, appearing "two-headed" until cytokinesis is complete. The chromosomes of euglenoids are permanently condensed and can often be seen with light microscopy.   Before cell division begins, the number of pellicle strips doubles so that the pellicle of each daughter cell will be made up of half of the new and half of the old strips.   Euglenoids sometimes form resting cysts if environmental conditions become unfavorable due to low nutrients levels or a low ratio of nitrogen to phosphorus. The cells swell and become rounder, lose their flagella, and develop more paramylon storage granules and a protective polysaccharide mucilaginous wall to contain the cells until conditions improve. Reproductive cysts continue to undergo cell division.