Suction infusories
| Suction infusories | ||||||||||||
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A suction infusor from the fresh water (left) catches a larger protozoan ( Colpidium sp .; Right) (microscope photo) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Suctoria | ||||||||||||
| Claparède & Lachmann , 1858 |
Suction infusoria (Suctoria) are a group of ciliate animals . Their adult forms have no lashes and are sessile to a surface . They catch other unicellular organisms with the help of one or more tentacles , which are also used to hold onto and suck out the prey.
features
The suction infusoria are 15 to 30 micrometers in size. The stalk with which they are stuck on the surface cannot be contractually shortened as in the case of the bell- shaped animals . Some species have a solid shell with an opening in the area of the tentacles and sometimes a second where the stalk rests on the base. This is called Lorica .
distribution
Suction infusories are common both in freshwater and in the ocean from the Arctic to the Antarctic . As epibionts, they usually colonize sessile organisms such as algae or bog animals , but can also be found on small crustaceans such as the amphipods or even parasitic copepods , on which they can often reach colonization densities of several thousand individuals per animal.
nutrition
The sucking infusoria do not have a cytostome like most other ciliate animals. Instead of a conventional cell mouth, they use tentacles to ingest food. The tentacles are supported by an outer ring of microtubules and an inner set of microtubule bands. The cytoplasm of captured protozoa is sucked directly into the food vacuole inside the suctories and digested there. Only the cell envelope (pellicle) of the captured prey remains.
At the tip of the tentacles is an extrusome called a haptocyst. With the help of this organelle, the prey can be held and killed. For this purpose, toxic secretions are released to the outside.
Multiplication
As with all ciliate animals, conjugation , the merging of two individuals for the exchange of genetic material, occurs with the sucking infusoria . Asexual reproduction occurs through budding , after which an adult individual releases several ciliated “larvae” into the water. These youth stages swarm out and soon settle on a suitable surface. They lose their cilia and develop a stalk and tentacles.
According to the type of budding, three groups of suctories are distinguished. While in the Exogenida (including the genera Podophrya and Sphaerophrya ) the buds appear on the cell surface, in the Endogenida (genera Tokophrya and Acineta ) they are formed inside the cell in a pocket and leave the cell body through an opening. In the evaginogenida, the buds are also formed inside the cell, the pocket then opens and releases the youth stages.
Systematics
Even if the adult suction infusor no longer has any cilia , the underlying infraciliature is retained. Their structure and other features, which were discovered through ultrastructural research, show similarities to the groups of the eyelash animal class Phyllopharyngea, to which the Suctoria are therefore also counted.
- Subclass: Suctoria
- Order: Exogenida
- Branches (selection): Phalacrocleptes , Stylostoma , Trophogemma , Dendrosomides , Loricodendron , Ophryodendron , Spelaeophrya , Ephelota , Parapodophrya , Mucophrya , Manuelophrya , Gajewskajophrya , Sphaerophrya , Kystopus , Podophrya , Tachyblaston , Metacineta , Thecacineta , Paracineta , Urnula , Corynophrya , Ophryodendron .
- Order: Endogenida
- Branches (selection): Dendrosoma , Lernaeophrya , Trichophrya , Platophrya , Heliophrya , Enchelyomorpha , Endosphaera , Trypanococcus , Pseudogemma , Acinetopsis , Solenophrya , Acineta , Pseudocorynophrya , Loricophrya , Erastophrya , Rhyncheta , Choanophrya , Tokophrya , Staurophrya , Allantosoma , Dendrosoma, Dendromectes .
- Order: Evaginogenida
- Genera (selection): Cyathdinium , Stylocometes , Cometodendron , Dendrocometides , Dendrocometes , Dactylosoma , Rhynchophrya , Cyclophrya , Prodiscophrya , Discophrya , Periacineta .
- Order: Exogenida
Individual evidence
- ↑ Gregorio Fernandez-Leborans, Mark Freeman, Regina Gabilondo and Christina Sommerville: Marine protozoan epibionts on the copepod Lepeophtheirus salmonis, parasite of the Atlantic salmon. Journal of Natural History, 39 (8), pp. 587-596, February 2005
- ↑ Gregorio Fernandez-Leborans, Carolin E. Arndt and Regina Gabilondo: protozoan Epibionts and Their Distribution on the Arctic ice amphipod Gammarus wilkitzkii from Spitsbergen, Norway. Arctic, Antarctic, and Alpine Research, 38 (3), pp. 343–356, August 2006 Abstract (Eng.)
- ↑ Systematics after: Denis H. Lynn: The Ciliated Protozoa: Characterization, Classification, and Guide to the Literature . 3rd edition, Springer, 2008 ISBN 140208238X p. 94 Online version from 2002 down to the genre level ( memento of the original from July 15, 2017 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
literature
- Sina M. Adl, Alastair GB Simpson, Mark A. Farmer, Robert A. Andersen, O. Roger Anderson, John A. Barta, Samual S. Bowser, Guy Bragerolle, Robert A. Fensome, Suzanne Fredericq, Timothy Y. James, Sergei Karpov, Paul Kugrens, John Krug, Christopher E. Lane, Louise A. Lewis, Jean Lodge, Denis H. Lynn, David G. Mann, Richard M. McCourt, Leonel Mendoza, Øjvind Moestrup, Sharon E. Mozley-Standridge, Thomas A. Nerad, Carol A. Shearer, Alexey V. Smirnov, Frederick W. Spiegel, Max FJR Taylor: The New Higher Level Classification of Eukaryotes with Emphasis on the Taxonomy of Protists. The Journal of Eukaryotic Microbiology 52 (5), 2005; Pages 399-451. doi : 10.1111 / j.1550-7408.2005.00053.x .
Web links
- Images and microscopic images (Engl.)