Trumpet animals
| Trumpet animals | ||||||||||||
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Roeseli stentor with a pearl-shaped macronucleus |
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| Stentor | ||||||||||||
| Oken , 1815 |
The trumpet animals ( Stentor ) are a genus of mostly firmly living ciliate animals .
features
Trumpet animals are among the largest single cells and can grow up to 2 mm long. When stretched out, they take on a funnel-shaped to trumpet-shaped shape, which is where the systematic name comes from: Stentor ( Greek Στέντωρ) is described in the Iliad as a man with a deafening voice. The front end, which carries the mouth opening (cytostome), which is often filled with spirally arranged eyelashes , is very wide. Towards the back, the cell body gradually narrows to a thin stalk with which the trumpet animal is firmly attached to the base. The rear end can be in a sheath separated from the animal itself. Several individuals can be connected to one another like a colony through this cover.
Contractile structures inside the cell allow the trumpet animals to change their shape flexibly. They then often appear elongated oval.
They can appear colorless like Stentor roeseli or be blue like the blue trumpet animal ( Stentor coeruleus ) or green like the green trumpet animal ( Stentor polymorphus ). The green color is caused by symbiotic algae.
A string of pearl-shaped macronucleus composed of several knot-like sections is characteristic of the trumpet animals .
Stentor sp.
Stentor sp.
Way of life
Trumpet animals only occur in fresh water . Usually they sit with their pointed ends on the ground, e.g. B. at the bottom of duckweed leaves or Myriophyllum and swirls with the help of her lash bacteria from which they feed mainly on cytostome. They can detach themselves from the subsurface and swim around with the help of cilia to fix themselves in a new location.
Preferably in spring there is sometimes a mass development of free-swimming specimens of Stentor coeruleus in quarry ponds . The animals can then unite to form "sooty" surfaces on the surface of the water and thus provide a form of water bloom . The probable cause of this phenomenon is the communal grazing on the surface of floating accumulations of tree pollen, because such “soot patches” have often been observed with a centimeter-wide yellow border.
Systematics
The Heterotrichea, to which the trumpet animals belong, were for a long time placed in the group of the Spirotrichea. However, recent research has shown that they are not closely related to the other groups of Spirotrichea. Above all, the subdivision of the macronucleus by external microtubules has led to them being placed as a subclass in the sub-strain Postciliodesmatophora today.
Individual evidence
- ↑ Systematics after: Denis H. Lynn: The Ciliated Protozoa: Characterization, Classification, and Guide to the Literature. 3. Edition. Springer, 2008, ISBN 978-1-4020-8238-2 , p. 94.
Web links
Paramecium (2007) | Tetrahymena (2009) | Eye animals (2010) | Dictyostelium (2011) | Acanthamoeba (2012) | Actinophrys (2013) | Trumpet Animals (2014) | Vampire Amoeba (2015) | Trichomonas (2016) | Diaphanoeca grandis (2017) | Dictyocysta mitra (2018) | Nuclearia (2019)