Bdelloidea
Various Bdelloida the genus Rotaria and their jaw structures
The Bdelloida place an order with about 300 known species within the rotifers ( Rotifera, Rotifera ) setting live mainly in freshwater and in moist to wet soils. They are characterized by their typical morphology and by their often egelartig creeping locomotion, which has given them their name (Greek βδελλα, bdella = " leech ").
Features
The front body of the Bdelloida has a robust, two-piece wheels organ as well as a so-called trunk ( proboscis ). Here, the wheels organ serves as with all other rotifers of food intake, the trunk, however, is adapted for creeping locomotion as a front attachment point. The rear attachment point provides the crawling foot with its own adhesive plate. The body contains the anterior intestinal region the strong gizzard ( Mastax ) and paired ovaries, which consist of a syncytial tissue. Males are not known at the Bdelloida, all kinds reproduce by parthenogenesis. In some gene segments (more precisely in the telomeres ) of the type Adineta vaga could show scientists genes of plants, animals, fungi and bacteria.
Habitat
The Bdelloida are very resistant and can survive in many habitats, especially in fresh water, in damp moss or wet earth. In masses they are found in eutrophic ( eutrophic ) ponds. During times of drought, many species, including about Macrotrachela quadricornifera, resting stages can form and are for anhydrobiosis, a form of cryptobiosis capable.
Taxonomy
The Bdelloida form a natural group, called a clade. Using various molecular biological studies and morphological comparisons was plausibly demonstrated that its closest relatives are the living parasitically scratch worms ( Acanthocephala ), which are considered in the classical system as a separate phylum in addition to rotifers.