Monomorphina pyrum is a freshwater single-celled organism characterized by its pear-shaped or pyriform cell structure. Enclosed within a flexible pellicle, it features a single, long flagellum extending from the anterior end, facilitating movement through water. The cell contains chloroplasts that are typically discoid or cup-shaped, essential for photosynthesis. Reproduction primarily occurs through asexual means via binary fission. Monomorphina pyrum thrives in freshwater environments such as lakes and ponds, contributing to ecosystem dynamics through its photosynthetic activity and role in nutrient cycling.