• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.3
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• pp.225-233
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• 2007

To verify which loop regions of 18S rRNA gene are suitable as species-specific genetic markers in ciliates, we analyzed the genetic variation of 18S rRNA gene among 9 Euplotes species (Hypotrichia : Ciliophora). In our result, no inter-specific variation was detected from V1, V3 and V5 regions, and the length of V7 and V8 are 44 bp and 79 bp, respectively, which are too short to make genetic marker. In contrast, V2 and V4 may be good candidate segments of species-specific diagnostic molecular markers because these two regions are most variable ($1.75{\sim}20.61%$) and showed good inter-specific phylogeny. Furthermore, the sequences of V2 and V4 are 123 bp and 306 bp, respectively in length which are enough to make species-specific marker.

• Journal of the korean society of oceanography
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• v.37 no.4
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• pp.201-211
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• 2002

We investigated the abundance and biomass of dinoflagellates and factors controlling their abundance in marine planktonic ecosystems in Korean coastal waters. The abundance of photosynthetic (PDNF) and heterotrophic dinoflagellates (HDNF) was in the range of 0.7${\times}$10$^2$ cells/1-14.0${\times}$10$^6$ cells/1 and in the range of 3.0${\times}$10$^2$ cells/1-6.47${\times}$10$^5$ cells/I, respectively. Their biomass was 0.5${\times}$10$^{-1}$-2.56${\times}$10$^4$ ${\mu}gC/I$ and 2.0${\times}$10$^{-1}$-1.5${\times}$10$^{2}$ ${\mu}gC/I$, respectively. In order to find factors controlling their abundance, stepwise regression and best subsets regression analyses were used. We found that during the summer the most important factors controlling PDNF abundance are DO, P, N and S (abiotic factors), and for HDNF, the abundance of zooplankton, ciliates and HF (biotic factors), and that high turbidity may effect the distribution of dinoflagellate species.

• Korean Journal of Ecology and Environment
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• v.41 no.4
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• pp.449-456
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• 2008

Recent studies reveal that the endocrine disrupter nonylphenol can also influence the growth of planktonic organisms. To clarify the effect of nonylphenol on the whole planktonic community, we monitored planktonic abundances after addition of nonylphenol using small-scale microcosms in a laboratory. Nonylphenol was added at final concentrations of 1.25 and $2.5{\mu}g\;L^{-1}$, close to the EC50 for the growth of the rotifer, Brachionus calyciflorus. Chlorophyll $\alpha$ concentration increased significantly between 2 to 5 days after nonylphenol treatment compared to the control. The abundance of the predominant phytoplankton, Stephanodiscus hantzschii, followed the same pattern as chlorophyll a concentration. While there was no negative effect on the abundance of ciliates and rotifers, crustacean zooplankton abundance was higher in nonylphenol treatments. Although the relationship did not reach significance, the growth rate of rotifers tended to decline with increasing nonylphenol dosing. It is likely that the decreased rotifer grazing on S. hantzschii caused significant increase in their abundance. This study emphasizes the importance of considering indirect effects of environmental pollutants when predicting the response of biological community to toxicant exposure.

• Animal Systematics, Evolution and Diversity
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• v.19 no.2
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• pp.237-244
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• 2003

Two epistylid peritrichous ciliates collected from the littoral aquatic plants at pond in a suburb of Ulsan, Korea were identified as Epistylis plicatilis Ehrenberg, 1831 and E. hentscheli Kahl, 1935. The description was based on the observation of living specimens and protargol impregnated specimens. This study is about redescription compared with original description. These species have not been reported in Korea and their characteristics are as follows: E. plicatilis is thin, long funnel form and has compact stalk, while E. hentscheli is unsymmetrical bell form and has hollow stalk.

• Ocean and Polar Research
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• v.30 no.4
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• pp.419-426
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• 2008

Ciliate plankton samples were collected biweekly from July 2006 to June 2008 in Jangmok Bay of Geoje Island. Species composition and abundances were analyzed by quantitative protargol stain and environmental parameters were also examined. A total of 88 ciliate species occurred during the study period, consisting of 22 tintinnids, 51 oligotrichs, and 15 other species. Higher ciliate abundances appeared from June to October during the warm season ($<20^{\circ}C$) and the maximum ($4.0{\times}10^4\;cells\;L^1$) in August, while the lower abundances were found during the cold season. The minimun ciliate abundance was found in November when water temperature rapidly decreased. The temporal succession of dominant species was very clear and opportunistic. Pelagostrombidium sp., Tontonia simplicidens, Helicostomella subulata, and Myrionecta rubra were co-dominant in summer while Rimostrombidium orientale occurred abundantly in winter. Strombidium tressum and S. compressum, eurythermal species, were observed during all seasons. Based on the species-specific ecology of ciliate plankton, it is suggested that the indicative ciliate species can be applied as a biological tool to detect environmental change in the southern coastal waters of korea.

• Animal Systematics, Evolution and Diversity
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• v.28 no.1
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• pp.29-35
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• 2012

Two Spirostomum species collected from freshwater in Korea were identified as S. caudatum (Muller, 1786) and S. teres (Claparede and Lachmann, 1858). They are recorded for the first time in Korea. The description was based on the observation of living specimens and protargol impregnated specimens. Diagnostics of these species are as follows. Spirostomum caudatum: body size $400-450{\times}20-30\;{\mu}m$ in vivo, shaped long and slender with a tapered posterior part, highly contractile; macronucleus ellipsoid; adoral zone of membranelles occupied 30% of body length; somatic kineties 14-22 in number. Spirostomum teres: body size $240-460{\times}25-40\;{\mu}m$ in vivo, shaped long and slender with a flattened posterior end, highly contractile; cortical granules arranged in 2-3 rows; adoral zone of membranelles occupied 50% of body length; somatic kineties 20-30 in number; macronucleus ellipsoid; micronuclei 2-3 in number. Spirostomum caudatum and S. teres are the most similar congeners, but they are different in the posterior part of body (tail-like posterior part vs. flattened posterior end), length of adoral zone of membranelles in body length (1/3 vs. 1/2), and the number of somatic kineties (14-22 vs. 20-30). These populations match with European populations in morphological characters.

• Ocean and Polar Research
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• v.32 no.1
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• pp.41-52
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• 2010

Daily samples were collected during summer in order to analyse changes in the mesozooplankton community and to identify the major environmental factors that may influence mesozooplankton abundance in Jangmok Bay. A single site in the bay was sampled 47 times from July to September 2003. Mesozooplankton community, hydrographic (watertemperature, salinity, dissolvedoxygen) and biological (chlorophyll-a, ciliates densities, Noctiluca scintillans densities) factors were determined. The mesozooplankton abundance varied remarkably from 954 to $14,816\;inds.\;m^{-3}$. The six taxa of Evadne tergestina, barnacle nauplii and cypris, Paracalanus parvus s.1., Acartia omorii, Penilia avirostris and Sagitta crassa dominated numerically, contributing 86% of total mesozooplankton abundance. Stepwise multiple linear regression analysis was applied to find correlation between environmental factors and fluctuation in the abundance of dominant species and mesozooplankton. A. omorii was significantly correlated with temperature and N. scintillans densities. E. tergestina was correlated with temperature, salinity, and ciliate densities, whereas P. avirostris was correlated with temperature and dissolved oxygen. Among the environmental factors, mesozooplankton abundance correlated most strongly with N. scintillans densities. Accordingly, N. scintillans may be a key player in controlling the fluctuation of mesozooplankton abundance as a strong competitor for same food resources.

• Animal Systematics, Evolution and Diversity
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• no.spc9
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• pp.1-9
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• 2016

Two Spirostomum species were collected from freshwater in Jindo Island, Korea and identified as Spirostomum ambiguum (Muller, 1786) Ehrenberg, 1835 and Spirostomum minus Roux, 1901. This study is the first known morphological record of these two species being found in Korea. The description is based on the observation of living specimens and protargol impregnated specimens. Diagnostics of Spirostomum ambiguum: body size $340-930{\times}45-80{\mu}m$ in vivo; long and slender body with truncated posterior part; macronucleus moniliform with 7-22 nodules; cortical granules irregularly arranged 4-5 rows in between somatic kineties; 24-58 somatic kineties arranged longitudinally; adoral zone of membranelles (AZM) covered about 60-80% of body length. Diagnostics of Spirostomum minus: body size $500-730{\times}35-45{\mu}m$ in vivo; long and slender body with truncated posterior part; macronucleus moniliform with 11-16 nodules; micronucleus 20-37 oval shape; cortical granules regularly arranged 3-4 rows in between somatic kineties; 20-30 somatic kineties arranged longitudinally; AZM covered about 40-50% of body length with 120-150 adoral membranelles.

• Journal of Environmental Health Sciences
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• v.31 no.1
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• pp.55-60
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• 2005

The occurrence and abundance of protozoa at advanced wastewater treatment plant were compared with operating parameters and effluent quality using statistical procedures. In correlation analysis between the distribution of protozoa and operating parameters, the distribution of protozoa was showed the operating condition of plant. Regression analysis between the distribution of protozoa and effluent quality up to 7 days, showed the R-square values of most regression equation were more than 0.6 and constant was higher than slope and could indicate effluent quality from sampling day to 7 days. Once enough data concerning protozoa, operating parameters and effluent has been gathered, the operator has a valuable tool for predicting plant performance and near-future effluent quality based on microscopic examination. Plant operator manipulates operating conditions if he knows near-future data of effluent is deteriorating. Perhaps more importantly it can be used to actually control the plant to adjust the operating conditions to obtain the protozoal populations that have been shown to provide the best effluent quality.

• Journal of the korean society of oceanography
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• v.37 no.2
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• pp.58-65
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• 2002

The study of microbial communities in sediments is impaired by the lack of reliable extraction methods. This study reports on the efficiency of recovery of a method for extracting bacteria, protists and diatoms from sandy sediments using a modified decant/fix method. The best extractions were achieved after fixation with a microtubule stabilising fixative and subsequent sonication for 80 seconds. We estimate that the efficiencies of recovery of bacteria and mixed heterotrophic flagellates were $96.4{\pm}3.5\%$ and $96.9{\pm}4.6\%$, respectively. Diatoms were recovered with an efficiency of 38-83% and varied considerably from species to species. This study suggests that the decant/fix method is effective in extracting small cells such as bacteria and heterotrophic flagellates, and that the efficiency of recovery of the method varies due to cell length and different types of organisms. When microbial carbon biomass had been underestimated by up to 32%, with much of that relating to larger cells such as microalgae and ciliates. We note that the corrected abundances may be still a subset of the total numbers present.