Subphylum Sarcodina
Belongs to: Phylum Sarcomastigophora
General Characteristics
- 1. Sarcodina is one of the major groups of protozoans characterized by their amoeboid mode of locomotion.
- 2. These organisms move and feed using pseudopodia, which are temporary extensions of their cytoplasm. The term "pseudopodia" means "false feet."
- 3. Movement via pseudopodia is known as amoeboid movement, which allows the organism to glide or ooze forward by constantly changing shape.
- 4. Pseudopodia are also essential for phagocytosis, a feeding process where the organism engulfs food particles, other microorganisms, or host cells.
- 5. The cytoplasm is differentiated into two parts:
- Ectoplasm: The clear, outer layer of the cytoplasm that is involved in movement.
- Endoplasm: The granular, inner region containing the nucleus and organelles.
- 6. Most sarcodines reproduce asexually through binary fission, where the organism divides into two genetically identical daughter cells.
- 7. They lack cilia and flagella in their active form, distinguishing them from other protozoan groups.
- 8. Most species are free-living and can be found in freshwater, marine, and moist soil environments.
- 9. However, several species are endosymbiotic, living inside the guts of animals as either harmless commensals or pathogenic parasites.