Extrusomes are membrane-bound structures in some eukaryotes which, under certain conditions, discharge their contents outside the cell. There are a variety of different types, probably not homologous, and serving various functions.
Notable extrusomes include mucocysts, which discharge a mucous mass sometimes used in cyst formation, and trichocysts, which discharge a fibrous rod.[1] The stinging nematocysts found in Cnidarian animals may be regarded as extrusomes as well. Extrusomes found in dinoflagellates are important in the formation of red and black tides.[citation needed] Ancoracysta twista, a Provoran eukaryote, immobilises its prey using a type of extrusome named an ancoracyst.[2]
