Bdelloida
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Various Bdelloida of the genus Rotaria and their jaw structures |
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| Scientific name | ||||||||||||
| Bdelloida | ||||||||||||
| Hudson , 1884 |
The Bdelloida represent an order with about 300 known species within the rotifers (Rotatoria, Rotifera). They live mainly in fresh water and in moist to wet soils. They are characterized by their typical morphology and by their often leech-like crawling locomotion, which gave them their name ( Greek βδελλα, bdella = "leech").
features
The front body of the Bdelloida has a pronounced, two-part wheel organ and a so-called proboscis. As with all other rotifers, the wheel organ serves to take in food, the trunk, on the other hand, is designed as a front attachment point for crawling locomotion. The rear attachment point is provided by the creeper with its own adhesive plate. In the anterior intestinal area, the trunk contains the strong chewing stomach (mastax) and paired ovaries , which consist of syncytial tissue. Males are not known in the Bdelloida, all species reproduce through parthenogenesis . In some gene segments (more precisely in the telomeres ) of the species Adineta vaga , scientists were able to detect genes from plants, animals, fungi and bacteria.
habitat
The Bdelloida are very resilient and can survive in many habitats, especially in fresh water, in damp moss or in wet soil. They can be found en masse in over-fertilized ( eutrophic ) small bodies of water. In drought, many species, including Macrotrachela quadricornifera , can develop permanent stages and are thus capable of anhydrobiosis , a form of cryptobiosis .
Taxonomy
The Bdelloida form a natural group called a monophylum . Various molecular biological investigations and morphological comparisons have plausibly proven that their closest relatives are the parasitic scratch worms (Acanthocephala), which in the classical system are considered as a separate animal strain in addition to rotifers.
supporting documents
Individual evidence
- ↑ Spectrum of Science: Masters in Genklau
- ↑ James R. Garey, Thomas J. Near, Michael R. Nonnemacher1, Steven A. Nadler: Molecular evidence for Acanthocephala as a subtaxon of Rotifera. Journal of Molecular Evolution 43 (3), 1996; Pages 287–292 ( doi: 10.1007 / BF02338837 )
- ↑ Martín García-Varela, Gerardo Pérez-Ponce de León, Patricia de la Torre, Michael P. Cummings, SSS Sarma, Juan P. Laclette: Phylogenetic Relationships of Acanthocephala Based on Analysis of 18S Ribosomal RNA Gene Sequences. Journal of Molecular Evolution 50 (6), 2000; Pages 532–540 ( doi: 10.1007 / s002390010056 )
literature
- Sievert Lorenzen: Rotifers (Rotifera), rotifers; in: Wilfried Westheide, Reinhard Rieger: Special Zoology. Part 1: Protozoa and invertebrates. Gustav Fischer Verlag, Stuttgart and Jena 1996; Pages 714-722. ISBN 3-437-20515-3
