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• Abstracts of V European Congress of Protistology
grazing activity. In conclusion, this study suggests that in Masan Bay heterotrophic protists control the growth of bacteria and phytoplankton, and heterotrophic protists represent an important link between bacterial & microalgal biomass and higher trophic levels.
COMMUNITY STRUCTURE AND DYNAMICS OF CILIATED PROTOZOA ALONG SALINITY GRA DIENTS AT SALTPANS OF THE YELLOW SEA Y. Lei1. J. Choi2, K. Xu1，H. Hong2
1 - Institute o f Oceanology, Chinese Academ y o f Sciences, 266071 Qingdao, PR China,2 Department of Oceanography, Inha University, Inchon 402-75], Korea. E-mail:
[email protected] -
The community structure and dynamics of ciliates along salinity gradients ranging from 28 psu to311psu at eight saltpans of the Yellow Sea, were investigated in April, June, August and September 2001. A total of 98 species of ciliates were identified using live observation and protargol staining techniques. The highest number of species (19) was found from the sample collected in April with the salinity up to 50 psu. With the salinity increasing beyond 265 psu, only one species, viz., Fabrea salina, could be observed. The ciliate abundance varied from 44 to 210,929 inds. 11and the maximum value was mainly contributed by Strombidium styliferum in August with the salinity of 36 psu. The biomass ranged between 2.39 and 9,866.63 (ig C 1"', and the maximum occurred in June due to the dominance of Fabrea salina when the salinity reached 148 psu. Both abundance and biomass decreased to the minimum with the salinity increasing to 311 psu in June. Statistical analyses show that neither ciliate abundance nor biomass was correlated to salinity, while species richness and diversity significantly decreased (p < 0.01) along the increased salinity gradients. Meanwhile, our data indicate that there were shifts of ciliate groups from oligotrichs towards hypotrichs to heterotrichs dominance with the increase of salinity. Supported by the National Science Foundation of China (No. 40576072) and the '100 Talents Project’ of Chinese Academy of Sciences.
THE BIODIVERSITY OF HELIOZOANS AND HETEROTROPHIC FLAGELLATES OF SEVERAL BOGS AND SMALL RIVER M.M, Leonov
Voronezh State University, Voronezh, Russia. E-mail:
[email protected]
Heliozoan and heterotrophic flagellate biodiversity in several bogs and one small river was investigated. Centrohelids Raphidiophrys intermedia, Acantocystispenardi， A. nichollsir A. takahashii，Pterocystis pinnata, Raineriophrys echinata, desmothoracid Clatrulina elegans, rotosphaerid Rabdiophrys sp., actinophryids Actinophrys sp.，and Actinosphaerium eichhornii have been found. 31 species of flagellates from 12 taxonomic groups were observed in the samples from acid bogs, but only 4
2007 species were found in the plankton of the small river. The representatives ofkinetoplastids and cercomonads were dominated in the samples in terms of species richness. Spumellasp., Bicosoecalacustris，Bodosaliens, Spongomonas uvella, Allantion tachyploon, Cercomonas agilis, and Protaspis simplex were the most common species. Some rare species such as Rhipidodendron splendidum，Dimastigella trypaniformis, Protaspis verrucosa, Apusomonas proboscidea， Aurigamonas solis， Reclinomonas americana have been identified. The majority of observed flagellates were bacterivores, but Rhynchobodo sp., Allantion tachyploon, Protaspis verrucosa, Aurigomonas solis were predators. 丁he bogs and river biodiversities considerably differed from each other. IDENTIFICATION OF TWO NOSEMA SPP. ISO LATED FROM P IE R IS RAPAE AND HEMEROPHILA ATRILINETA J.P. Liu1' J. Hao1，S.T. Liao2
1- South China Agriculture University, China,2 Guangdong Provincial Agricultural Academy Institute, China. E-mail:
[email protected] -
Microsporidia are a group of obligate intracellular parasites. Some microsporidia play an important role in biological control of the silkworm Pebrine disease. This paper is focused on life cycle studies， ultrastructural identification, and genetic variations (in SSU-rDNA and ITS region sequences) of two microsporidia, isolated from Pieris rapae (CFD) and Hemerophila atrilineta (SCH). Following results were obtained. (1) Life cycles of CFD and SCH, were similar, except for duration oflife cycles, which were obviously shorter in CFD (72h) than in SCH (96h). (2) The spores collected from original hosts varied in shape. The spore shape was tending to become uniform (oval and smooth) after propagating the isolates in the experimental host (silkworm) repeatedly. Both isolates had three-layered spore wall, isofilar polar filament, bipartite polaroplast. and two nuclei. The number of polar filament coils and the size of posterior vacuole varied depending on generation. (3) Phylogenetic analyses of CFD and SCH isolated from original hosts, based on partial SSUrDNA sequence put these microsporidia into Nosema/ Vairimorpha clade. If microsporidia were passed through silkworms 4 times, the sequences obtained from harvested spores fell into the clade of true N. bombycis group. (4) ITS region of two isolate displayed high variations. Different clones from the same PCR amplication also significanly varied. Multiple alignment revealed three highly varied sites in the ITS region of the studied isolates. Our results suggest that both isolates belong to the genus Nosema, and that microsporidia might possess a selective adaptability and potential to differentiate in the alternative host. Supported by NSF grant 30671588.
