extrusomes, trichocysts

Description:

Frontonia (front-own-ee-a) is a peniculine ciliate and as such is closely related to the familiar Paramecium. It has many crystalline inclusions called trichocysts (a special form of extrusome). When stressed the crystalline structure of these changes, and they are expelled in large numbers and forceably from the cell. This action can force the cell away from the noxious stimulus. The expelled, the trichocysts look like little spears attached to the slide or to the substrate. Phase contrast.