Trichocyst

[3] A trichocyst can be found in tetrahymena and along cila pathways of several metabolic systems.

It is also a structure in the cortex of certain ciliate and flagellate protozoans consisting of a cavity and long, thin threads that can be ejected in response to certain stimuli.

Trichocysts may be widely distributed over an organism or restricted to certain areas (e.g., tentacles, papillae, around the mouth).

Mucoid trichocysts are elongated inclusions that may be ejected as visible bodies after artificial stimulation.

The functional significance of other trichocysts is uncertain, although those of Paramecium apparently can be extruded for anchorage during feeding.