• Journal of Environmental Science International
• /
• v.20 no.9
• /
• pp.1087-1093
• /
• 2011

The mixotrophic marine ciliate Mesodinium rubrum possesses a highly modified algal endosymbiont as a nutrition source for the species. Accordingly, we assumed that the species can reflect the ecotoxicity on marine producer (as phytoplankton) and consumer (as zooplankton) both. A series of experiments were conducted to identify the potential of the species as a standard test species for marine ecotoxicological study. The comparison of species sensitivity on reference toxic materials was made using potassium dichromate for phytoplankton and copper chloride for zooplankton. The ciliate revealed the highest sensitivity on both reference materials among the seven test species including phytoplankton, benthic copepod and rotifer species. The toxicity end point of the species was 72hr-$EC_{50}$=1.52 mg/L (as potassium dichromate) estimated by population growth inhibition (PGI), which is more sensitive than the most sensitive phytoplankton Skeletonema costatum (72hr-$EC_{50}$=3.05 mg/L). As comparison to rotifer, it also revealed higher sensitivity on copper chloride; 72hr-$EC_{50}$=0.38 mg/L for ciliate and 48hr-$EC_{50}$=0.48 mg/L for rotifer. Also, the elutriate toxicity test of various ocean disposal wastes were conducted to identify the potential of ciliate toxicity test application using industrial waste sludges. The toxicity of leather processing waste sludge was highest on the ciliate, followed by dyeing waste sludge and dye production waste sludge as an increasing order of toxicity. 72h-$EC_{50}$ of ciliate PGI test was 1.83% and that of S. costatum 3.84% for leather waste sludge which showed highest toxicity. The toxicity test results also revealed that the highest sensitivity was observed on ciliate species on ocean disposed sludge wastes. Also, ciliate toxicity test well discriminated the degree of toxicity between sludge sources; 72h-$EC_{50}$ values were 1.83% for leather processing waste sludge, 16.75% for dye production waste sludge and 27.75% for textile production waste sludge. Even the laboratory culture methods of the species were not generally established yet, the species has high potential as the standard test species for marine toxicity test in terms of the dual reflection of phyto- and zooplankton toxicity from single test, sensitivity and test replicability.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.32 no.3
• /
• pp.317-319
• /
• 1999

The ciliate, Vorticella was often observed in the rotifer mass culture tanks as common co-existing organism. This Vorticella performed as a predator for aquatic bacteria population in the rotifer mass culture tanks. This study was carried out to investigate a cyst formation medium of Vorticella in the laboratory for keeping Vorticella seed. The test organism Vorticella sp. was isolated from culture water of rotifer mass culture tanks. The cyst of Vorticella was formed by dried-method for the formation and maintainance of cyst. MCCF (Marine Ciliate Cyst Formation) medium was used for cyst formation (incystment), preservation and return to moving cell (excystment) of the marine ciliate, Vorticella sp. The cyst shape and size were ellipical type and $30.51 \pm1.98\;\mu$m (Avg. $\pm$ SD) of minor axis and $28.89 \pm2.12\;\mu$m (Avg. $\pm$ SD) of minor axis (n=10), The Vorticella cyst was kept in the room temperature ($10\~35^{\circ}C$) and total dark condition (24D:0L) during 1 year. The preserved cyst was transferred to moving cell state (excystment) only by the addition of fresh sea water in the MCCF medium. The five Vorticella sp. moving cells of excysted from cysts showed the growth up to 912$\pm$64 cells/10 ml in MCCF medium during the culture period of 16 days. This MCCF medium was very useful tool for cyst formation and species preservation of marine ciliate Vorticella.

• Journal of Aquaculture
• /
• v.21 no.3
• /
• pp.167-171
• /
• 2008

Common co-existing organism Euplotes (Ciliate, Protozoa) well often observed in the rotifer mass culture tank of marine fish larval rearing stations. Ciliate protozoa (Euplotes) competed to condensed food (micoralgae, Nannochloropsis oculata) with rotifer (Brachionus rotundiformis). As results, rotifer density was rapidly decrease, and what is more, the rotifer was wiped out by dominant bacteria species at that time.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.26 no.3
• /
• pp.248-262
• /
• 2021

Marine planktonic ciliates include two major groups, loricated tintinnids and naked oligotrichs. The study of marine ciliate plankton in Korea began with taxonomic efforts on tintinnids based on the morphology of lorica, a vase-shaped shell. Despite polymorphism in the lorica, it is utilized as a key characteristic in identification of tintinnid species. However, oligotrichs have been studied only recently in Korea due to challenges associated with the observation of ciliary arrangements and the technical development for cell staining. Species diversity and phylogenetic classification of the ciliates have been informed by recent advances in morphological and molecular analyses. Illustrations of the planktonic ciliate in Korea have been published on the basis of taxonomic data of tintinnids and oligotrichs. Planktonic ciliates acting as the major consumers of pico- and nanoplankton as well as the prey of mesozooplankton, has been monitored by spatial and temporal investigations in Korean coastal waters. A practical approach addressing the limitations and potential of marine ciliate studies in Korea is proposed here to improve the data quality of planktonic ciliates, providing an enhanced basis for quality control of ciliate monitoring.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.12 no.3
• /
• pp.178-185
• /
• 2007

Myrionecta rubra Jankowski 1976(=Mesodinium rubrum Lohmann 1908), a mixotrophic ciliate, is very common and often causes recurrent red tides in diverse marine environments. Since the report on the first laboratory strain of this species in 2000, papers on its novel ecological role and evolutionary importance have been high lighted. This review paper is prepared to promote the de novo recognition M. rubra as a marine mixotrophic species. M. rubra is a ciliate which is able to photosynthesize using plastids originated from cryptophyte (including Teleaulax sp. and Geminigera sp.) prey cells (i.e. kleptoplastidic ciliate). Recently, novel bacterivory of M. rubra was firstly reported. Thus, the nutritional modes of M. rubra include photosynthesis, bacterivory, and algivory. In turn, M. rubra was reported as the prey species of metazoan predators such as calanoid copepods, mysids, larvae of ctenophore and anchovy, and spats of bivalves. In addition, it was reported that dinoflagellate Dinophysis causing diarrhetic shellfish poisoning is one among the predators of M. rubra. Thus, M. rubra, a marine mixotrophic ciliate, may play a pivotal role as a common linking ciliate for the flow of energy and organic material in pelagic food webs.

• Journal of fish pathology
• /
• v.18 no.1
• /
• pp.19-28
• /
• 2005

Scuticociliatosis has badly settled one of most damaging diseases during the seedling production process of olive flounder. Paralichthys olivaceus in Korea. We isolated a new type of Scuticociliate from flounder. The parasite metamorphoses to ciliate and cyst phases with each other by environmental changes and survive for a relatively long span. The ciliate was measured average 41.8 ${\mu}m$ in length and 21.0 ${\mu}m$ in width, and cyst was 17.0 ${\mu}m$ and 13.5 ${\mu}m$, respectively. Nutritional condition was determined as a major parameter of metamorphosing between ciliate and cyst stages. The ciliate transforms to a cyst stage because of food shortage, and the cyst returns to a ciliate stage with a favorite environmental condition and shows active growth and reproduction. The ciliate multiplied at the maximal density of $2.9 {\times} 10^5 {m\ell}^{-1}$cells in vitro cultivation at $15 ^{\circ}C$temperature using MS BHI medium and bacterial food sources. The ciliate could be proliferated at a 2.5 to $30 ^ \circ}C$ temperature range, pH 6 to 9, and 1 to 55 ppt salinity. Particularly, it survived over one week at $0 ^{\circ}C$temperature showing a high resistance against unfavorable environmental conditions. And the cyst survived for 320 days in the condition of $5 ^{\circ}C$with no feeding, but its survival period was markedly shortened in higher temperature conditions. The chemotherapeutants (formalin and hydrogen peroxide) were clarified as effective chemicals against the ciliate during in vitro trials, but the effect of therapeutants differed in proportion, depending upon the density and the bathing time of chemical compounds.

• Journal of fish pathology
• /
• v.12 no.2
• /
• pp.101-105
• /
• 1999

In a survey of net-caged yellowtail Seriola quinqueradiata in the southern parts of Korean Peninsula, we found infestations of ciliate in the gills of the moribund fish during the abnormally elevated temperature. The ciliate was very similar to genus Colpoda Muller, 1773 on morphological and reproductive characteristics. Histopathological changes revealed that the ciliate invaded gills only, causing extensive destruction of the gill filaments including lamella without any clinical signs found in the other organs and tissues. This is the first record of the parasitic ciliate in cultured yellowtail.

• Ocean and Polar Research
• /
• v.31 no.1
• /
• pp.77-95
• /
• 2009

Ciliate abundance and biomass were determined at three anchored stations in the Han River estuary trimonthly from May 2006 to February 2008. The total abundance of ciliates ranged from 0-13,853 cells $l^{-1}$ and biomass ranged from $0.00-73.98\;ugC\;l^{-1}$. Owing to the large seasonal temperature variation (range 0.20-$27.2^{\circ}C$), ciliate abundance displayed marked seasonal variation, being higher in summer than in other seasons. Tintinnids dominated the ciliate communities at station YC where suspended sediment was highest. Difference of ciliate biomass between ebb tide and flood tide were irregular. Seasonal variations of ciliate carbon biomass at each station were related to temperature, suspended sediment and chl.a, especially nano chl.a. Geographical variations of ciliate carbon biomass in each season were related to suspended sediment and salinity.

• Journal of Species Research
• /
• v.9 no.4
• /
• pp.455-461
• /
• 2020

Marine benthic ciliates were collected from four rocky intertidal pools along the eastern and southern coasts of Korea from 2012-2013. Ciliate specimens were examined by observing living and stained cells. Four ciliate species were new to Korea based on morphological characteristics as follows. (1) Aspidisca polypoda (Dujardin, 1841): small bean-shaped (ca. 30 ㎛), eight conspicuous dorsal ridge, polystyla-arrangement of frontoventral cirri; (2) Epiclintes auricularis auricularis (Claparède & Lachmann, 1858): tripartite and auriform body (ca. 300 ㎛), 46 adoral membranelles, one or two frontal and 23 transverse cirri, 12 oblique fronto-midventral rows; 59 left and 71 right marginal cirri; (3) Pseudochilodonopsis marina Song, 1991: reniform body (ca. 50 ㎛), two obliquely positioned contractile vacuoles, seven left and five right kineties, five fragmented preoral kineties; (4) Dysteria semilunaris (Gourret and Roeser, 1888): oval-shaped (ca. 30 ㎛), two longitudinally positioned contractile vacuoles, conspicuous longitudinal grooves on both plates, four or five right kineties, one short row below frontoventral kineties.

• Animal Systematics, Evolution and Diversity
• /
• v.21 no.1
• /
• pp.21-30
• /
• 2005

The morphogenesis of the marine ciliate, Pelagostrobilidium simile Song and Bradbury, 1998, was investigated using pyridine silver carbonate impregnation. The morphogenesis of P. simile is of hypoapokinetal mode. The oral primordium of P. simile commences slightly below the external membranelles (EM) with the proliferation of an anarchic field. Somatic ciliature in proter and opisthe of P. simile are derived from the old structure with the proliferation of the basal bodies during the dividing process. Parental oral apparatus of P. simile is inherited by the proter, and no reorganization of oral apparatus was observed in the parental oral infraciliature.