Acoelomorpha

Waminoa sp. on a bubble coral

The Acoelomorpha ("A" = not, no; " coela " = coelom, intestine) are a taxon of very small worm -like animals ( Turbellaria ) and thus belong to the phylum flatworms ( Platyhelminthes ) were counted initially to the class of flatworms, 2004 by Baguña & Riutort were elevated to the rank of a tribe and were of Philippe and colleagues assigned in 2011 as a sub-tribe of the Xenacoelomorpha.

Studies of Ribosomal DNA as well as the number and type of Hox genes came to the conclusion that most Untertaxa the flatworms must be made within the Urmünder ( Protostomia ) to the Lophotrochozoa, while the Acoelomorpha to Neumündern ( deuterostomes ) belong.

There are very small animals that have no digestive tract. Externally, they resemble the flatworms, live in the sea, between the particles of sediment, plankton or on the surface of algae or coral. As the flatworms they lack the coelom.

Some Acoelomorpha example the genus Waminoa live with zooxanthellae in symbiosis, feeding, among others, their photosynthetic products. Convoluta lives in symbiosis with the unicellular green alga Tetraselmis convolutae.

Inside systematics

Acoelomorpha to include two classes Acoela and Nemertodermatida:

• Acoelomorpha Ehlers, 1985 (2 classes) Class Nemertodermatida Karling, 1940 ( 2 families) Family Ascopariidae Sterrer, 1998 (2 genera, 4 species)
• Family Nemertodermatidae Steinböck, 1930 (4 genera, 5 species)

• Family Diopisthoporidae Westblad, 1940 ( 1 genus, 5 species)
• Clade Bitesticulata Jondelius, Wallenberg, Hooge & Raikova, 2011 Family Paratomellidae Dörjes, 1966 ( 2 genera, 3 species)

• Clade Prosopharyngida Jondelius, Wallenberg, Hooge & Raikova, 2011 Family Hallangiidae Westblad, 1946 (2 genera, 2 species)
• Family Hofsteniidae Bock, 1923 ( 3 genera, 6 species)
• Family Solenofilomorphidae Dörjes, 1968 ( 5 genera, 10 species)

• Family Dakuidae Hooge, 2003 (3 genera, 21 species )
• Family Isodiametridae Hooge & Tyler, 2005 ( 22 genera, 90 species )
• Family Otocelididae Westblad, 1948 ( 5 genera, 9 species )
• Family Proporidae Gra? , 1882 ( 14 genera, 62 species )

• Family Convolutidae Gra? , 1905 (24 genera, 114 species)
• Family Mecynostomidae Dörjes, 1968 ( 11 genera, 32 species )