Biodiversity of Neotropic Soil Ciliates

Ciliates belong to the protists, which embrace the world of heterotrophic and autotrophic "Protozoa" or "Infusionstierchen", that is, single-celled organisms of microscopic size (<1 mm), altogether about 250,000 named species, extant and fossil. Ciliates are that group of protists which have many hairs (cilia) on the body surface and in the mouth. The cilia serve for locomotion and food acquisition. About 10,000 named species belong to this taxon, which is, due to its unique nuclear apparatus (somatic macronucleus and generative micronucleus), usually considered as a distinct phylum. Many of them are excellent bioindicators for water and soil quality. The 10,000 species known, most from freshwater and the sea, are possibly only a small portion of the actual diversity; there is evidence that 80% of the ciliate diversity is still undescribed. Where are this many undescribed species? A considerable portion is contained in soil, where we discovered about 600 new (undescribed) species, and the statistical treatment of the data indicates that there are many more! The ciliates living in soil are poorly known, especially in the tropics. Thus, we collected over 200 samples in Central and South America during the past 10 years. Half of them have been investigated and showed a great diversity of ciliates, including many undescribed species. Thus, the research objectives and perspectives of the proposed project can be summarized as follows and match the "Year of Biodiversity" declared by the UN: " to obtain reliable morphological and molecular information on soil ciliates from the neotropics by describing the species discovered in the samples mentioned above; " to obtain reliable information on geographical distribution and endemism of soil ciliates, by comparing the data with similar FWF-supported studies we did in Africa; " to compare the neotropic soil ciliate community with that occurring in tank bromeliads, a group of rosette plants occurring only in the neotropics; " to educate young scientists in alpha-taxonomy (= description of species), a discipline threatened to become extinct in Europe and the USA, at least as concerns heterotrophic, free-living protists. Both the postdoc and the graduate student will be trained also in molecular methods in laboratories of colleagues specialized in this field. The results will be published as individual papers in peer-reviewed scientific journals and as a summary in a book, as we did with Namibian soil ciliates. We have great experience in studying soil ciliates and our laboratory is in this respect unique worldwide. The project is planed for three years. The support needed amounts to about 400,000 Euro (~ 500, 000 US Dollar), mainly to finance a postdoc, a graduate student, and a technician.

Soil is the basis of our life. All that grows, flourishes and dies get back to the soil where it become mineralized and available for new life. The decomposition and mineralization are performed mainly by soil organisms. This requires a high biodiversity which is the subject of our project. There are hundreds of thousands of species in soil, ranging from single-celled organisms (viruses, bacteria, fungi, protists) to mammals (e. g. moles). The real biodiversity of soil globally is not known. Hundreds of new species are described every year and there seems to be no end. In our project, we investigate terrestrial protists, viz., the ciliates or infusoria, of which we have discovered more than 500 new species during the past 30 years. Now, we investigated soil ciliates in South America because this continent has a large general biodiversity and soil ciliates have never been investigated.Ciliophora or ciliates (Infusoria) are single-celled organisms (Protozoa) of microscopic size (usually < 1 mm). Their diversity (number of species) and phylogeny (relationships) are poorly known. Ciliates occur in most water- containing habitats, i.e., in marine and limnetic ecosystems and in and on multicellular animals and plants. As the name says, ciliates have covered the body with fine hairs (cilia), used for swimming and food acquisition. When the environmental conditions become unfavourable, they have the ability to produce a dormant stage, called resting cyst. During encystment, the cells round up and secret a wall so resistant that the fragile cells can survive for years. Ciliates belong to the heterotrophic protists, together with amoebae, flagellates and sporozoans, which lack chlorophyll and must thus feed for nutrition. As yet, about 10.000 ciliate species have been described; however, this are possibly only 20% of the actual diversity, which is poorly known because most ciliates are harmless and thus comparatively uninteresting for most scientists.We concentrated our investigations on 70 samples from Venezuela. They contained almost 400 ciliate species of which more than 100 were undescribed. According to a main goal of the project, we published the new and poorly known species in a monograph with about 1300 pages and which will become available in November. Special species and their molecular sequences were published in 24 peer-reviewed papers. With these descriptions the species become available for ecologists. Some of the new species are so-called flagships which are very likely endemic to the neotropics and thus support the moderate endemicity distribution model of protists. Alltogether, the scientific goals of the project have been reached.But we did not have success with another main goal, viz. the education of protist taxonomists who are pressingly needed worldwide. Four PhD students tried it but gave up because of insufficient interest and talent.