Cystodinedria
- Cystodinedria inermis (ref. ID; 3726)
- Cystodinedria maxima (ref. ID; 3726)
- Cystodinedria setosa Pascher (ref. ID; 3726)
Descriptions
Cell size in our sample of C. inermis varied from 22.0 to 57.0 x 17.0 to 47.5 um. Color varied from bright olive green to brown to orange. Each cell contained one to several reddish-brown globules similar to those described in the Stylodinium cycle. A typical dinocaryon was present and a mucliagenous attaching disc was detected. Most specimens had settled on empty Spirogyra sp. and Oedogonium sp. cells. The stage which we were identified as C. inermis in our sample preyed on 1 to 8 cells in row before resting on an intact Spirogyra or Oedogonium cell. During its movement to an intact filament cell its shape was very irregularly ovoid. Without doubt this giant cell was identified as Cystodinedria maxima Popovsky. Its multiplication by means of two zoospores was descried earlier by Popovsky (1961, 1967). Recently we recorded several manners or reproduction of that organism, a "so-called Cystodinedria". We described four previously unknown, new alternate life cycles. We have often observed orange Cystodinedria sp., but we have never seen orange amoeboid stage released as we have in the Stylodinium life cycle. (ref. ID; 3726)
- First cycle: Two heliozoids are released (Actinophrys sol) from Cystodinedria maxima after its protoplast divides - for details see the Stylodinium cycle. Only once did we observe the change of one heliozoan stage into Cystodinium phaseolum Pascher. One of two heliozoids moved across intact Oedogonium or Spirogyra cells. Axopods shortened, the heliozoid settled saddle-like on the filament cell and within 5 sec, after penetration (enzymatically) of the cell wall the Spirogyra or Oedogonium chloroplast shriveled and was consumed within 10 min by the heliozoan stage. This settled stage resembled some suctorian species from the genus Trichophrya Clap. & Lachman. The heliozoan stage then moved to the next cell and began the process again; we have observed this stage preying on from 1 to 8 cells in a row. The settled heliozoan stage has been observed changing in two ways: (1) the attached heliozoan stage changes into the settled amoeboid stage, releases a part of protoplasm (microspore?) and leaves the filament. It then immediately fuses with a what may have been a microspore. The amoeboid stage (Vampyrella lateritia in non-heliozoan stage) penetrates the Spirogyra or Oedogonium cell (enzymatically) by means of a filopodium and preys upon the cell contents. This free swimming amoeboid sage settles, shortens its filopodia and becomes Cystodinedria shaped. (ref. ID; 3726)
- Second cycle: The attached heliozoan stage which we provisionally named "suctorian" after absorbing its axopods becomes a Cystodinedria-shaped cell and continues preying on several filament cells. Then secretes a mucilage envelope and in 10 min leaves the filament with the mucilage becoming nontransparent. We identified this amoeboid stage with lobopodiars Amoeba verrucosa Ehrenb. This amoeba moved very slowly so that at first time it seemed to be motionless. All such amoebae had dead Oedogonium zoospores nearby. We saw Oedogonium zoospores approach the amoebae, become motionless, and be slowly engulfed. As they engulfed 1 or 2 Oedogonium zoospores, the cells shell opened on the opposite side, and a small piece of protoplasm with very short filopodia left and changed into small amoebae. These small amoebae preyed upon Oedogonium or Spirogyra cells, suddenly stopped swimming and assumed the Cystodinedria form. Fusion or the next fate of the four detected motile gymnodinioid shaped spores in unknown. (ref. ID; 3726)
- Third cycle: The heliozoan stage specimen changes into shelled heliozoid which were refer as the "heliozoan stage" of Vampyrella lateritia. In some features it resembles the heliozoid Dinamoeba mirabilis Leidy. In some heliozoid stages we observed shells shed and the organism settling as a Cystodinedria shaped cell on a filament. These shelled heliozoids also moved very slowly so that they at first glance seemed to be motionless (see the alternate cycle of Amoeba verrucosa). All had dead Oedogonium zoospores nearby. We saw Oedogonium zoospores and also ciliates approach the heliozoan stage, became motionless, and be (only Oedogonium zoospore) engulfed. Most ciliates regained movement after a few minutes. If 1 or 2 Oedogonium zoospores were engulfed, the shell was opened on the opposite side and a small pieces of protoplasm containing one or two red-brown globules left and quickly changed into two amoebiod stages. These amoebiod stages were undifferentiated from the ones from the Amoeba verrucosa cycle and preyed upon Oedogonium or Spirogyra filaments. After several hr amoeboid forms stopped swimming and assumed the Cystodinedria sessile form. (ref. ID; 3726)
- Fourth cycle: It begins with the shell shed organism = Vampyrella lateritia in heliozoan form or Dinamoeba mirabilis and changed into the attached stage Actinophrys sol. This last stage has been observed preying upon from 1 to 4 cells of Oedogonium or Spirogyra in a row. It suddenly changes itself into an amoeboid form (Vampyrella lateritia) and leaves the filament. After a short period of swimming it settles on the Oedogonium or Spirogyra filament and starts to prey upon several cells. During this process the cell shape is more constant and resembles a Cystodinedria. The axopods are absorbed and one can see spicules alone that are typical for Cystodinedria setosa Pascher. Over a period of an hour these spicules are absorbed or are changed into short, quickly moving, finger lobopodia and after approx. two hr the cells membrane becames fixed, wrinkled and non-transparent. We presumed this cell was a resting stage or cyst. (ref. ID; 3726)