Morphology, Ontogeny And Phylogeny Of Hypotrichia And Euplotia Ciliates (Protozoa, Ciliophora)

Ciliated protozoa have proved to be one of the most important components of the microbial food web in almost all aquatic and terrestrial ecosystems worldwide, because they conume a significant portion of bacterial productivity, enhancing nutrient cycles and energy flow to organisms at higher trophic levels. They also play important role in molecular biology, development and evolution, and cell biology because of their complicated morphogenetic process, unique conjugation pattern and special nuclear dualism. As the most complex and highly differentiated group, hypotrichs has been a research hotspot especially on its diversity and morphorgenesis. However, over 300 years research left numerous taxon to be rechecked and confusion to be revised. Recently, it is one of the most active research areas of protozoology, that using morden microscopic obeservaton and silver-staining technique, combining with ontogentic research and molercular data to explore the biodiversity and phylogenetic relationships among ciliated protozoa.During 2010 to 2015, founded by the Natural Science Foundation of China, fauna survey of ciliated protozoa in sandy beach, mangrove wetland, estuary, freshwater and soil habitats along the coast of Shandong and Guangdong province. It mainly focused on hypotrichous and euplotid ciliates. This work including 11 genera and 16 species, among which one new genus and six new species were established, detailed redescription were supplied for known species. In addition, ontogenetic processes of eight species were studied; small subunit (SSU) rRNA gene sequences data for metioned species are provieded, and phylogenic trees are constructed for resolution of controversial phylogenetic problems.The main achievements are summarized as follows:Taxonomic part1. Pseudogastrostyla g. n.New genus Pseudogastrostyla g. n. was established based on the arrangement of frontal-ventral-transverse cirri and development pattern of dorsal kinety. The new genus was diagnose as:Oxytrichids with more than 18 frontal-ventral-transverse cirri, of which some cirri are arranged in short rows. Undulating membranes in an Oxytricha-pattern. Dorsomarginal kinety present. No dorsal kinety fragmentation during morphogenesis.2. Establishment of six new speicesAs the result of fauna survey and detailed identification, six new species are found: Bistichella cystiformans, Neourostylopsis flava, Sterkiella vorus, Urosomoida subtropica, Pseudogastrostyla flava, Euplotes parafinki.3. Redescription of 10 known speciesInvestigate and improved diagnosis of six long-term confused species provided (Deviata abbrevescens, Deviata rositae, Anteholosticha randani, Anteholosticha antercirrata, Oxytricha balladyna, Euplotes amieti); Provide detailed redescription of four speices based on new populations (Pseudourostyla subtropica, Euplotes aediculatus, Diophrys japonica, Pseudodiophrys nigricans).Morphogentic part1. Ontogenetic investigation of Bistichella cystiformans show the origin of the two long frontoventral rows and frontal-ventral-transverse cirral anlage Ⅵ provides no transverse cirrus. Morphogentic pattern of the genus Bistichella was provided.2. Supplement investigation of ontogentic process of Deviata abbrevescens show the parental dorsal kineties preserved during division, discussion of the family classification of Deviata were provided based on morphogenetic characters.3. Detailed ontogenetic investigation of Oxytricha balladyna and Sterkiella vorus show the conservative in morphogenesis among the genus of family Oxytrichdea.4. Detailed ontogenetic investigation of three euplotes(Euplotes parafinki, Euplotes amieti, Euplotes aediculatus) provided the pattern of development of their frontoventral cirri and caudal cirri; resuls show the conservative in morphogenesis of the genus Euplotes.5. Ontogenetic investigation of Pseudodiophrys nigricans provided the process of development of the undulating membranes; ontogenetic characteristics comparison confirmed the establishment of the genus Pseudodiophrys.Phylogenetic part:The small subunit (SSU) rRNA gene sequences of all metioned species were provided. Sequences comparisons and phylogenetic trees based on the SSU rRNA gene sequences data were studies. Meanwhile, phylogenetic relationship among stichotrichid, urostylid, oxytrichid and euplotid ciliates were carried out.