Turbellaria
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| Image:Bedford's Flatworm.jpg Bedford's Flatworm, Pseudobiceros bedfordi
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(Acoela) |
Turbellaria are a group of generally small (<1 - 60cm) and free-living members of the flatworm phylum Platyhelminthes. It is nowadays mostly considered obsolete (polyphyletic), and the Acoela and Nemertodermata are excluded from the class into a phylum of their own (Acoelomorpha).
Their locomotion depends on cilia. Most turbellaria are carnivorous, and actively scavenge for food. Most species are marine and freshwater dwellers, but some have evolved to dwell on humid land, as well.
The planarian Dugesia is a common representative of class Turbellaria.
Summary of features for Class Turbellaria (L. turbellae = a combination, aria = like):
-no mitosis in somatic cells; new cells made by totipotent stem cells
-free-living (non-parasitic) or symbiotic flatworms
-dorsoventrally flattened triploblasts with a blind gut
-well-defined nervous system with sense organs (ocelli and ciliary chemoreceptors)
-ganglia concentrated into a brain at one end of the body (cephalization)
-a simple life cycle
-monoecious (simultaneous hermaphrodites)
fr:Planaire hr:Virnjaci it:Turbellaria lt:Blakstienotosios kirmėlės mk:Трепчести црви pl:Wirki pt:Turbellaria simple:Turbellaria sk:Ploskule sr:Трепљасти црви sv:Virvelmaskar zh:涡虫纲
