What are Mesozoa?

Mesozoa are small, simple, worms or blob-similar parasites that were once considered to be intermediates between protozoa (movable unicellular organisms) and metazoa (multicellular animals). However, they are now generally considered to be degenerate metazoa, ie Metazoans, who came from more complex animals, but simplified secondary. However, there is no strong consensus yet and it is possible that Mesozoa is indeed just basal metazoans.

While the term "Mesozoa" was to refer to a natural group that consisted only of exclusive offspring that were now known - all were given, which were given, which were given - all were given, which were given, which were given their own spars. Trichoplax adhaerens ), orthonectide (small parasites of areas, molluscs and echinoderms) and rhombozoa (renal parasites of cefalopods as squid). Mesozoa are remarkableIn its simplicity - although they have a dual and organized tissue, this differentiation is relatively simple - for example, cell types can be layered.

Trichoplax adhaerens , the only species of phylum placozoa is a soft body animal 0.5 mm across, reminiscent of a giant amoeba. It is also called "tablet animals", named tricoplax for its ability to adhere to surfaces, including microscopic slides or glass pipettes. In 2006, Dellaporta et al introduced a complete mitochondrial genomic sequence tricoplax and has shown that it is the most famous living metazoan phylum, which branches before Cnidarians (jellyfish and corals). Cnidarians may have evolved from the body as simple as tricoplax .

Another of the Mesozoa, orthonectis, consists of a wall of cilted cells surrounding the nucleus of reproductive cells. OrthonectideThey are mobile, swimming of their cilia and have larval stage and also different men and women. The phylum includes only 20 species, rhopalura Ophiocomae is the best known. Orthonectis was once considered to be closely related to rhombozoa, another mesozoan group, although it is now known that they are not related.

rhombozoa (also known as dicymides), other parasites of Mesozoan phylum, range from 0.1 to 9.0 mm and living octopus kidney. Like other microscopic animal, Rotifers, Dilyemidsare Eutelic, which means that all adults have a constant number of cells. Instead of adding new cells to growth, the size of each individual cell simply increases. Dicymides are most often found in a slight bentic environment and rarely in tropical areas.