Monograph of the Urostylids (Ciliophora, Hypotrichia)

Research project P 14778 Monograph of the Urostyllids (Cillophora, Hypotrichia) Helmut BERGER 27.11.2000 By Helmut Berger, Consulting Engineering Office for Ecology, Salzburg, Austria. For nonitaxonomists, revisions and monographs are often the main source of information about a group of organisms. Monographs are also appreciated by specialists because timeconsuming enquiries about, for example, nomenclature, taxonomy or ecology can be, avoided. Furthermore, the diversity of a higher taxon is thoroughly documented. The urostylids are a species-rich group of hypotrichous ciliates common in most terrestrial, limnetic, and marine habitats. The most important feature of the urostylids are the midventral cirri, which extend in the midline of the ventral surface and are arranged in zigzag pattern, Since 1758, the begin of zoological nomenclature, about 35 urostylid genera comprising circa 250 species have been described. On the assumption that 30-50 % of them are species indeterminata, synonyms or species belonging to other higher taxa, about 125-175 valid species are known at, present. The last detailed revision of hypotrichous ciliates was written by Kahl (1932), a brief key to urostylids was provided by Borror and Wicklow (1983). The monograph of the urostylids will be organized like the monograph of the oxytrichids already published by the applicant (Berger 1999). A copy of this almost 1100 pages long treatise, which ,was written without any financial support, should serve as example. The monograph of the urostylid will be published by Backhuys Publishers (The Netherlands). The project is planned over a three year period and comprises the following parts: (1) Critical inventory and "monographic" treatment of the available data since 1758. The data about urostylids are distributed in more than 2000 papers. About 50 % of the three year period are estimated for that part. (ii) Morphological investigations of species using live observation and silver staining. About 20 % of time are estimated. (III) Investigation of ontogenesis of some key species (mainly type species). Ontogenetic data are often very useful for the analysis of. phylogenetic relationships of hypotrichs (Berger and Foissner 1997). About 20 % of time are estimated. (Iv) Cladistic analysis of urostylids using traditional methods and computer programs. About 5 % of time are estimated. (v) Investigation of some key species with molecularbiological methods in collaboration with the group of Univ.- Prof. Dr. Martin Schlegel, University of Leipzig, Germany. Within the oxytrichid hypotrichs, molecularbiological investigations provided many, very useful data elucidating the phylogeny. About 5 % of time are estimated for isolation and cultivation. My experience tells me that 5.5 printed pages on average are necessary for a thorough revision of a ciliate species. Thus, the monograph of the urostylids will be about 700 to 1000 pages long. The manuscript will be submitted camera-ready. I hope that this monographic series about the hypotrichous ciliates will be a standard for the next 50 to 100 years! Berger H (1999), Monographiae Biologicae, 78, 1-1092 (Kluwer). Berger H, Foissner W (1997), Archiv fOr Protistenkunde, 148, 125-155. Borror AC, Wicklow, BJ (1983), Acta Protozoologica, 22, 97-126. Kahl A (1932), Tierwelt Deutschlands, 25, 399-650.

The Urostyloidea (= urostyloids) are a group of ciliates (= Ciliophora) whose members occur in all major biotops, that is, freshwater, sea, and soil. The goal of the project was to summarise the present knowledge (supplemented by own data) about these single-celled organisms in a critical revision. The book will have about 1200 printed pages and will be published by Backhuys, The Netherlands. The classification of the hypotrichous ciliates is basically done according to the arrangement of the cirri, which are compact bundles of cilia on the ventral side of the dorso-ventrally flattened cells. The urostyloids are characterised by the zigzagging arranged ventral cirri which form the so-called midventral pattern. This pattern originates by the longitudinal arrangement of cirral pairs which are produced from oblique cirral anlagen during cell division. In the present review 32 genera comprising 148 species are considered as valid. The urostyloids are divided into four subgroups, the Holostichidae, the Bakuellidae, the Urostylidae, and the Epiclintidae. The genus Uroleptus is also characterised by zigzagging ventral cirri. Thus, it was included in the urostyloids in previous classifications. However, molecular data suggest that Uroleptus is more closely related to other hypotrich taxa than to typical urostyloid representatives as, for example, Urostyla and Holosticha. To harmonise morphological and molecular taxonomy, we established the CEUU (Convergent Evolution of Urostylids and Uroleptids) hypothesis (Foissner et al. 2004). It suggests that the zigzagging cirral pattern evolved convergently by inserting additional anlagen between the six anlagen which belong to the ground pattern of the Hypotrichs. This hypothesis can also explain some deviating cirral patterns in other groups, for example, that of the oxytrichids Pattersoniella and Territricha. Beside molecularbiological features, the CEUU-hypothesis is supported by at last one good morphological feature (Berger 2005). The revision should not only serve as standard for ciliatologists, but it should also be a "field guide" for limnologists, soil biologists, and marine biologists.