Ref ID : 7556
Susanne Kuhlmann and Klaus Hausmann; [Untersuchungen zu Nahrungserwerb und Nahrungsaufnahme bei Homalozoon vermiculare, Stokes 1887 2. Mucocysten, Konocysten, Toxicysten]. Protistologica XVI(1):125-134, 1980
Reprint
In File
Notes
Homalozoon vermiculare has three types of extrusomes: mucocysts, conocysts and toxicysts. In the resting state, the mucocysts have a paracrystalline substructure and this changes into a filamentous network during the discharge of the organelle. The membrane of the mucocyst appears to vesiculate after discharge of its contents. Conocysts have two concentric layers which envelop an axial rod. After ejection the axial rod has the same appearance as in the resting state, but the result of the organelle has a homogeneous appearance. The toxicysts are of two kinds; short (ca. 2 µm) and long (ca. 10 µm). In the resting state, the short toxicyst contains a tubule which is surrounded, in its central region, by finer tubular elements. Cross sections of the long toxicysts reveal several concentric tubules and a kidney shaped mass. The expulsion of the short toxicyst involves an evagination of the tubule. In the long toxicyst, this evagination is combined with the telescopic discharge of an inner tube, which, however, remains within the tubule.