• Archaea
• biogeography
• Ciliates
• description
• ecology
• endosymbiont
• microorganism
• species
• taxonomy

The author of the present thesis spent six months in India to collect and identify known and novel species of ciliates and investigating the presence of symbionts, with the help of the Marine Biology Laboratory of the Zoological Department of Andhra University.
The author carried out samplings in different regions of this Country, namely in many areas of Andhra Pradesh state, in the Chilka Lake of Odisha state and in some localities of West Bengal in the surrounding of Kolkata. Further laboratory analysis and experiments were subsequently carried out in the Biology Department of Pisa University.
Results achieved during the PhD course are divided in two main parts in the frame of the present doctoral thesis. In the first part of the manuscript are exposed those results related to the Indian ciliate biodiversity (Chapter 1) and to ciliate morphological, molecular and phylogenetic characterizations, in particular about members of Oligohymenophorea (Chapter 2), Plagiopylea (Chapter 3) and Armophorea (Chapter 4). Moreover, an updated check-list of ciliates from India has been reported (Chapter 5) to better comprise the status of art at whole Country level.
The second part of the thesis has results related to Indian ciliate endosymbionts, namely the characterization of the novel species “Candidatus Gortzia shahrazadis” from Paramecium multimicronucleatum (Chapter 6), the southern record of Holospora obtusa and the subsequent revision of the genus distribution (Chapter 7), the description of the cytoplasmatic microbial consortium of Euplotes woodruffi (Chapter 8), and methanogens Archaea symbionts of anaerobic ciliate species such as Plagiopyla spp., Metopus sp., Brachonella spiralis, and Chaenomorpha sp. (Chapter 9).