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Abstract: This paper includes the proposal of a new genus for a new species of peritrichous ciliate, Apocarchesium rosettum n. gen., n. sp., as well as the first description by modern techniques of another peritrich, Ophrydium eichornii Ehrenberg, 1838. The genus Apocarchesium is separated from the related genus Carchesium by the appearance of the stalk and the arrangement of zooids, and diagnosed as follows: colonial vorticellid, with all zooids attached in rosette fashion to the tip of their common stalk, which is unbranched and contracts spirally; pellicle with parallel silverlines. The morphology, infraciliature, and silverline system of both species were investigated by observation in vivo and silver-staining methods. [Copyright &y& Elsevier]

The distribution of the main microbial loop components (bacteria, heterotrophic nanoflagellates (HNF), ciliates) was investigated at three sites: the inner, central and outer regions of Hiroshima Bay, Seto Inland Sea, Japan, in summer (June and August 1996 and July 1997). At the inner region site, lower salinity and higher concentrations of nutrients and chlorophyll a were observed than in the other regions. Bacterial, HNF and ciliate biomasses ranging from 32.6 to 170.1 µg C/L, from 1.5 to 84.8 µg C/L and from 0.1 to 91.7 µg C/L, respectively, were generally highest at the inner region site. The ciliate assemblages were mostly dominated by mixotrophic aloricate ciliates in the surface and near-surface layers. The relationship between the biomass of aloricate ciliates and their prey organisms showed significant linear correlations at the three sites. The slope of the regression line was lowest and the X -axis intercept of the line was highest at the inner region site, possibly suggesting relatively low energy transfer efficiency between them in this site. Hence, high biomass of less than 20 µm phytoplankton, bacteria and HNF may not be efficiently utilized by ciliates in the inner region of Hiroshima Bay, compared with the situation in other regions of the bay. [ABSTRACT FROM AUTHOR]

Photosynthetic bacterium (PSB) was isolated from sediment samples of Yamagawa Bay, Kagoshima, Japan. Phylogenetic analysis results of PSB isolate were closely related to Rhodobacter sphaeroides, purple non-sulfur photosynthetic bacteria (PNSB). Pink-colored smooth edges of single bacterial colonies were observed after 3-5 days of incubation period on Basic I medium agar plates. Rhodobacter sphaeroides microscopic examination showed a short rod cell (1-2 µm length) with round ends. Sediment and water samples used for ciliates cultivation were collected from Kuwano-ura Bay, Koshiki Island, Japan. Ciliates were cultivated using fish meal with radish leaves medium (MI), with sediment into MI (MII) and algae media (MIII). The use of the algae media (MIII) in cultivation mixture produced the highest total number of ciliates. Big size ciliates were identified as Euplotes minuta and Cyclidium varibonneti, while small size was identified as Micrometopion nutans, based on PCR-DGGE. When ciliates were cultured with the PSB isolate, Rhodobacter sphaeroides as a feed, ciliates grow to 2,081 individual ml -1 72 hrs later. These findings indicate that PNSB can be used to promote ciliates growth.