extrusome

Extrusomes are specialized structures found in certain single-celled organisms, primarily protozoans. These structures are located within the cell's cortex and can be ejected in response to stimuli.1

There are different types of extrusomes:
* Mucoid trichocysts: Elongated inclusions that can be expelled as visible bodies.1
* Filamentous trichocysts: Found in organisms like Paramecium, these are discharged as filaments and may be used for anchorage during feeding.1
* Toxicysts: Typically found near the mouth of carnivorous protozoans, these extrude a filament that can paralyze or kill prey, aiding in food capture and defense.1

Protozoans themselves are single-celled eukaryotes that perform all life processes within a single cell enclosed by a plasma membrane. They utilize various organelles, including vacuoles, for functions like digestion and maintaining water balance.23