Tintinnid Species Research Articles

Diatom bloom trigger notable variations in microzooplanktonic ciliate composition, body-size spectrum and biotic-abiotic interaction in the Arctic Ocean

How microzooplanktonic ciliate adaptative strategies differ across diatom bloom and non-diatom bloom areas in the Arctic Ocean remains poorly documented. To address this gap, two different situations were categorized in the Arctic Ocean at summer 2023: diatom bloom stations (DBS) (genus Thalassiosira, chain-like) and non-diatom bloom stations (nDBS). Total abundance of ciliate at 3 m and 25 m in DBS was 2.8 and 1.8 folds higher than in nDBS, respectively. Aloricate ciliates were singled out in both DBS and nDBS, whilst their average abundance and biomass of large size-fraction (>50 μm) in former were 4.5–5.6 folds higher than in latter. Regarding tintinnids, high abundance of Ptychocylis acuta (Bering Strait species) mainly occurred at DBS, coupled with distribution of co-occurring Pacific-origin species Salpingella sp.1, collectively suggested a strong intrusion of Pacific Inflow during summer 2023. Additionally, presence of high abundance of Acanthostomella norvegica and genus Parafavella in nDBS might indicate the trajectory of the Transpolar Drift. Alternatively, tintinnids can serve as credible bioindicators for either monitoring currents or evaluating microzooplankton Borealization. Average abundance of total ciliate within 15–135 μm body-size spectrum in DBS was higher than nDBS. Moreover, spearman's rank correlation between biotic and abiotic analysis revealed that temperature and dissolved oxygen at DBS determined tintinnid species richness and ciliate total abundance, respectively. The results clearly demonstrate that remarkable divergences in large size-fraction of ciliate abundance between DBS and nDBS validate their irreplaceable role in controlling phytoplankton outbreak and associated biological processes in polar seas.

Insights into the pelagic ciliate community in the Bering Sea: Carbon stock, driving factors and indicator function for climate change

Microzooplankton carbon stock and its biotic-abiotic interactions are important linkage in marine carbon biogeochemistry, which remain poorly documented in the Bering Sea. In the summer of 2019, we investigated the community structure of pelagic ciliates from the surface to bottom (or up to 200 m) in the Bering Sea. High abundance and biomass of ciliate occurred mainly in waters shallower than 50 m. The average carbon stock of ciliates were 350.0 ± 96.4 mg C m−2 and 218.4 ± 148.8 mg C m−2 in oceanic and shelf regimes, respectively. Aloricate ciliates were the dominant group, with an average abundance proportion to total ciliates of over 80% at each depth. We identified 45 tintinnid species belonging to 15 genera, including 7 new record species in the Bering Sea. The abundance proportion of their lorica oral diameter (LOD) size-classes at each sampling depth was mainly within the fractions of 12–16 μm and 24–28 μm. Furthermore, both Codonellopsis frigida and Parafavella jorgenseni can act indicator species of Pacific inflows based on their distributions. Strong correlations were reflected between abiotic environmental factors and the distribution of these indicator species, for instance, the positive correlation between salinity and the cold water-adapted species C. frigida, confirming the dominant role of bottom-control on the ecosystem. Our study laid a foundation for deep understanding of ciliate community at summertime of the Bering Sea, and its role in driving biogeochemical fluxes.

Seasonal organization of tintinnid community by temperature preference and LOD size-class in a subtropical brackish embayment

Abstract Most annual studies of tintinnid and phytoplankton in coastal habitats are influenced by alien species introduced by water masses exchange, and therefore cannot be used as direct evidence for exploring the mechanism of annual succession in indigenous community. For brackish communities, very limited annual studies exist because of the difficulty of conducting stable sampling in the transition between freshwater and seawater. The special topography of Xiangshan Bay isolates the external water mass and provides a suitable habitat for exploring the annual succession mechanism of the brackish tintinnid community. In this study, samples were collected from seven stations in Tie Harbor, Xiangshan Bay (East China Sea) during 10 months from 2022 to 2023. A total of 23 tintinnid species of five genera were identified throughout the year. These tintinnid species can be clustered into four seasonal groups, winter, summer, autumn and spring-autumn, with three temperature preferences. The Lorica Oral Diameter (LOD) size-class of each tintinnid species, which determines the food item size of tintinnid, separated their different ecological niches within each seasonal group. The seasonal succession of tintinnid community in Xiangshan Bay was organized by both temperature preference and LOD size of the tintinnid species.

Diversity and dynamics of tintinnids communities from Romanian Black Sea, in 2021

Tintinnids are tiny ciliates from microzooplankton that are very important due to their implication in the microbial food web and for the fact that in the last two decades a considerable number of non-indigenous species have entered and acclimatized in the Black Sea basin. The paper presents the species diversity and dynamic of microzooplanktonic tintinnids’ abundance as a result of two cruises carried out in May-June and August-September 2021, along the Romanian Black Sea coast. We identified 23 tintinnid species in total, with a higher diversity in the surface layer compared to those of depth. The species Eutintinnus sp. and Salpingella decurtata were found eclusively in the 10 m layer. Tintinnopsis cylindrica represented 74% of the mean biomass of tintinnid’s community from May-June, the best quantitative representation recorded in the Romanian coast's northern sector. Amphorellopsis acuta represented 91% of the mean biomass of tintinnid’s community in August-September. The biotic component was also correlated with temperature and salinity to give more information regarding spatial and temporal variations from one area to the other. The findings contribute to the knowledge of microzooplankton communities in the Romanian Black Sea region. The data on species composition, abundance distribution, and environmental correlations enhance our understanding of the ecological dynamics and potential ecological implications of tintinnid communities. This study brings valuable information to the understanding of the microzooplankton component in the Black Sea ecosystem.

Biogeography of marine tintinnid ciliates (Ciliophora, Tintinnida): a Scale-Dependent Model

The distributions of tintinnid ciliate species were analyzed in the Mediterranean, Black and Azov seas, and the Arctic, Indian, Atlantic, Pacific and Southern oceans. Data on the distribution of 916 tintinnid species were processed. It was found that distribution of tintinnids corresponds both to Ubiquity model (EiE) and Moderate endemicity model (MEM), depending on the used spatial scale. As a result, a Scale-Dependent Model (SDM) of marine tintinnid ciliate distribution was proposed.

Latitudinal pronounced variations in tintinnid (Ciliophora) community at surface waters from the South China Sea to the Yellow Sea: Oceanic-to-neritic species shift, biotic-abiotic interaction and future prediction

The oceanic-to-neritic species shift of microzooplanktonic tintinnids and their interaction with relevant abiotic variables are two crucial processes in the marine ecosystem. However, these processes remain poorly documented in China's marginal seas. In the summer of 2022, we investigated the community structure of pelagic tintinnids in surface waters from the South China Sea (SCS) to the Yellow Sea (YS), passing through the East China Sea (ECS). A number of 58 species from 23 genera were identified, with 36 and 22 species belonging to oceanic and neritic genera, respectively. The abundance proportion of oceanic and neritic genera exhibited a decreasing and increasing trend, respectively, from the SCS to YS. Furthermore, four distinctive tintinnid community groups were classified based on cluster analysis using tintinnid species and abundance data, and the position of southern Taiwan Strait was identified as the “Shift Point” for oceanic-to-neritic species dominance. The top two tintinnid species in each group showed distinct variations in body size. Additionally, multivariate biotic-abiotic statistical analyses revealed that temperature determined tintinnid species richness, while temperature, salinity, Si(OH)4, and Chl a determined tintinnid abundance. Our study provides a substantial foundation for recognizing the oceanic-to-neritic species shift of tintinnids in the China's marginal seas, and highlights the role of biotic-abiotic factors in driving biogeochemical fluxes and the potential response of microzooplankton to future climate change.

Community structure of tintinnids (Protozoa: Ciliophora) in the eutrophic environment (the Golden Horn Estuary, Turkey)

The distribution of tintinnid species and their associations with environmental variables were evaluated in the eutrophic Golden Horn estuary ecosystem. The samples were collected from two stations monthly between October 2009 and September 2010. The study determined 17 tintinnid species belonging to five families and nine genera. In the study, the results of environmental variables such as temperature, salinity, dissolved oxygen, pH, Secchi disk, chlorophyll-a, and nutrients were recorded synchronously with tintinnid samples. Also, the Shannon-Weaver diversity index, canonical correspondence analysis (CCA) and the two-way indicator species analysis (TWINSPAN) were applied to the data. According to this statistical analysis, the diversity was high in spring and summer, and it was determined that temperature was the main factor affecting tintinnid composition. Also, Tintinnopsis beroidea could be used as a potential indicator species in ascertaining the NH4–N, and Codonellopsis schabi and Tintinnopsis acuminata were detected to be winter and spring seasons indicators.

Variability of tintinnid ciliate communities with water masses in the western Pacific Ocean

Abstract Tintinnids play a pivotal role in the marine plankton ecosystem and are model organisms in plankton studies. However, the biogeographic distribution type and community variation of tintinnids from coastal to open waters in the western Pacific have never been studied before. In the present study, 42 surface tintinnid samples were collected from coastal water to the western Pacific warm pool. A total of 84 tintinnid species were identified. The Kuroshio intrusion has obvious influence on tintinnid distribution and community structure. Fifty-two tintinnid species with relatively high occurrence frequency were classified into neritic, transitional, Kuroshio, warm-pool and cosmopolitan species. We verified the existence of tintinnid transitional species and community in Mixed Water between Neritic and Kuroshio Waters (KW). Tintinnid species richness, abundance, Shannon-Wiener index and Pielou index were higher in the KW than in the Warm-pool Water. The community complexity and stability was highest in the KW. Our findings provide a profound understanding of planktonic biogeography and community variation from nearshore to open waters in tropical and subtropical oceans.

Diel variations in planktonic ciliate community structure in the northern South China Sea and tropical Western Pacific

Though diel variations are geographically widespread phenomena among phytoplankton and zooplankton, knowledge is limited regarding diel variations in planktonic ciliate (microzooplankton) community structure. In this study, we analyzed diel variations in community structure of planktonic ciliates in the northern South China Sea (nSCS) and tropical Western Pacific (tWP). Hydrological characteristics during day and night were slightly different over both the nSCS and tWP, while ciliate average abundance at night was clearly higher than in the day in the upper 200 m. In both the nSCS and tWP, abundance proportions of large size-fraction (> 30 μm) aloricate ciliates at night were higher than in the day. While for tintinnids, abundance proportion of large lorica oral diameter at night were lower than in the day. The relationship between environmental factors and ciliate abundance pointed out that depth and temperature were main factors influencing aloricate ciliate and tintinnid in both day and night. For some dominant tintinnid species, chlorophyll a was another important factor influencing their diel vertical distribution. Our results provide fundamental data for better understanding the mechanisms of planktonic ciliate community diel variation in the tropical Western Pacific Ocean.

Full-depth vertical distribution of planktonic ciliates (Ciliophora) and a novel bio-index for indicating habitat suitability of tintinnid in the Arctic Ocean

Despite the planktonic ciliate importance in the microzooplankton compartment, their full-depth vertical distribution in the Arctic Ocean was poorly documented as well as the related variations in different water masses. The full-depth community structure of planktonic ciliates was investigated in the Arctic Ocean during summer 2021. The ciliate abundance and biomass decreased rapidly from 200 m to bottom. Five water masses were identified throughout the water column and each one exhibited a unique ciliate community structure. Aloricate ciliates were singled out as the dominant group with average abundance proportion to total ciliates at each depth >95%. Large (>30 μm) and small (10–20 μm) size-fractions of aloricate ciliates were abundant in shallow and deep waters, respectively, which revealed an anti-phase relationship in vertical distribution. Three new record tintinnid species were found during this survey. Pacific-origin species Salpingella sp.1 and Arctic endemic species Ptychocylis urnula occupied the top abundance proportion in the Pacific Summer Water (44.7%) and three water masses (≥38.7%, Mixed Layer Water, Remnant Winter Water, Atlantic-origin Water), respectively. The habitat suitability of tintinnid abundant species was characterised by the Bio-index revealing a distinct death-zone for each species. Variations in survival habitat of abundant tintinnids can be regarded as indicators for the future Arctic climate change. These results provide fundamental data on the microzooplankton response to the intrusion of Pacific waters into the Arctic Ocean upon its rapid warming.

Hydrographic Feature Variation Caused Pronounced Differences in Planktonic Ciliate Community in the Pacific Arctic Region in the Summer of 2016 and 2019.

Planktonic ciliates are an important component of microzooplankton, but there is limited understanding of their responses to changing environmental conditions in the Pacific Arctic Region. We investigated the variations of ciliate community structure and their relationships with environmental features in the Pacific Arctic Region in the summer of 2016 and 2019. The Pacific water was warmer and more saline in 2019 than in 2016. The abundance and biomass of total ciliate and aloricate ciliate were significantly higher in 2019 than those in 2016, while those of tintinnid were significantly lower. The dominant aloricate ciliate changed from large size-fraction (> 30 μm) in 2016 to small size-fraction (10–20 μm) in 2019. More tintinnid species belonging to cosmopolitan genera were found in 2019 than in 2016, and the distribution of tintinnid species (Codonellopsis frigida, Ptychocylis obtusa, and Salpingella sp.1) in 2019 expanded by 5.9, 5.2, and 8.8 degrees further north of where they occurred in 2016. The environmental variables that best-matched tintinnid distributions were temperature and salinity, while the best match for aloricate ciliate distributions was temperature. Therefore, the temperature might play a key role in ciliate distribution. These results provide basic data on the response of the planktonic ciliate community to hydrographic variations and implicate the potential response of microzooplankton to Pacification as rapid warming progresses in the Pacific Arctic Region.

Tintinnid ciliates (marine microzooplankton) of the Ross Sea

For the Ross Sea, the only Marine Protected Area in Antarctica, available data on the tintinnid ciliates of the marine microzooplankton are mostly limited to nearshore waters near Terra Nova Bay or the vicinity of the McMurdo Sound. Here, we report results from a geographically extensive sampling across the Ross Sea conducted in December 2020. Material from plankton net tows (20 µm mesh), made at 38 stations spanning over 30° of latitude, was examined. We found 11 tintinnid species of varying commonality or rarity, many showing considerable morphological variability that is here documented. We found four forms that had not been previously reported from the Ross Sea. Based on our findings and previous reports, we assembled a species accumulation curve showing the growth in the inventory of tintinnid species recorded from the Ross Sea as a function of sampling effort and time since 1983. Extrapolation of the species accumulation curve, derived from sampling over the last 37 years, indicates that continued sampling will likely provide new species records, suggesting that the Ross Sea is under-sampled at present. This complicates efforts to detect temporal changes in species compositions, at least with regard to tintinnid ciliates. Comparing species accumulation curves for the Ross Sea and the relatively well-studied Weddell Sea, it appears that the Ross Sea may be more species-rich.

Neritic tintinnid community structure and mixing with oceanic tintinnids in shelf waters of the Pacific Arctic Region during summer

Tintinnids play an important role in the microbial food web and consist of neritic and oceanic ones biogeographically. Neritic tintinnid species are mainly present in continental shelf areas. Knowing their community structure is thus critical to better understand the ecological function of microzooplankton in the Pacific Arctic Region. During the summer of 2019, neritic tintinnid diversity, vertical distribution, and mixing with oceanic tintinnids were investigated from the Bering Sea to the Chukchi Sea. A total of 19 neritic tintinnid species belonging to 5 genera were identified. All of the neritic species were reported in waters south of the Pacific Arctic Region. No endemic Arctic neritic tintinnid was found. The distributions of nine abundant neritic species exhibited no difference between the Bering Sea and Chukchi Sea. Abundant neritic species were divided into surface- and bottom-dwellers according to their vertical distributions. Bering Shelf Water was dominated by neritic bottom-dwellers, while Anadyr Water was inhabited by neritic surface-dwellers. Neritic and oceanic tintinnids from the Pacific were mainly advected into the Chukchi Sea by Bering Shelf Water. Neritic bottom-dwellers could be mixed into surface waters possibly due to upwelling caused by Pacific Inflow Water flow over shelves. In surface waters, the neritic tintinnid community represented <50% of the total tintinnid abundance. Our results will help to predict future changes in the microzooplankton community under the influence of global warming and increasing Pacific Inflow Water on the Pacific Arctic Region shelf as well as in the Arctic basin.

Micro-/Meso-Scale Distinction and Horizontal Migration of Tintinnid (Ciliophora: Tintinnida) Assemblages in Three Regions Around the North Pacific Ocean

We explored the relationships among different tintinnid populations on micro-, meso-, and basin-scales from three regions across the Pacific Ocean, including the Costa Rica Dome (CRD) in the Eastern Pacific Ocean, the Celebes Sea (CS), and the Tokara Strait (TS) in the Western Pacific Ocean. We quantified the species occurrence, vertical and biogeographic distribution patterns, and morphological parameters of tintinnid assemblages. A total of 46 tintinnid species were observed, with more than half (63.0%) in common among the three areas, accounting for 97.1% of the total abundances. The numerically abundant forms remained more or less the same set of species in the three areas. However, community structure analyses, in terms of species, lorica oral diameter (LOD) size classes, and genera, revealed clear distinctions among different regions, as well as among different water depths. A Lagrangian simulation of passive dispersal in ocean currents across the Pacific Ocean, supported the hypothesis that greater similarity between tintinnid populations in the CS and TS (relative to CRD), was related to ocean circulation linkages between the populations. A latitudinal decline of tintinnid species richness was observed, mainly as a result of a decline of redundant species and warm-water species in colder areas. These data provide information unique insight into population variability of microzooplankton communities on micro- to meso- and even large scales in the world oceans.

Planktonic Tintinnid Community Structure Variations in Different Water Masses of the Arctic Basin

Information on tintinnid community structure variations in different water masses in the Arctic Basin is scarce. During the summer of 2020, tintinnid diversity and vertical distribution were investigated in the Arctic Ocean. A total of 21 tintinnid species were found in five water masses and each water mass had a unique tintinnid community structure. In the Pacific Summer Water (PSW), Salpingella sp.1 occupied the top abundance proportion (61.8%) and originated from the North Pacific. In the Remnant Winter Water (RWW), Acanthostomella norvegica occupied the top abundance proportion (85.9%) and decreased northward. In the Mixed Layer Water, Pacific Winter Water, and Atlantic-origin Water, Ptychocylis urnula had the highest abundance proportion (67.1, 54.9, and 52.2%, respectively). The high abundance distribution area of Salpingella sp.1 and A. norvegica were separated by the boundary of the Beaufort Gyre and Transpolar Drift. The above species could be indicator species of each water masses. The highest abundance proportion of Salpingella sp.1 contributes 81.9% to the dominance of 12–16 μm lorica oral diameter in the PSW, which indicated that the preferred food items of tintinnid were also getting smaller. The occurrence of North Pacific tintinnid in the PSW might be due to the increasing Pacific Inflow Water. Further studies are needed to explore the lasting period of this species and whether it can establish a local population under rapid Arctic warming progress.

渤海湾浮游纤毛虫丰度和生物量的周年变化

PDF HTML阅读 XML下载 导出引用 引用提醒 渤海湾浮游纤毛虫丰度和生物量的周年变化 DOI: 10.5846/stxb202101210222 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目(41806205);泰山学院引进人才科研启动基金项目(Y-01-2021014);天津市农业发展服务中心青年科技创新项目(ZXKJ201915);天津市科技重大专项与工程(18ZXRHSF00270) Annual variation of abundance and biomass of planktonic ciliates in the Bohai Bay,China Author: Affiliation: Fund Project: Natural Science Foundation of China [NSFC No. 41806205], Research Foundation for Talented Scholars of Taishan University (Y-01-2021014), Youth Science and Technology project of Tianjin Agricultural Development Service Center (ZXKJ201915), Tianjin Science and Technology Major Programs and Projects (18ZXRHSF00270) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为了解渤海湾浮游纤毛虫丰度、生物量和种类组成的周年变化,于2019年7月-2020年6月在渤海湾一个站位进行每月1次共12个航次浮游纤毛虫样品的采集。样品按照Utermöhl方法进行分析,通过倒置显微镜镜检,计算纤毛虫的丰度和生物量。无壳纤毛虫和砂壳纤毛虫出现峰值的时间不同,无壳纤毛虫丰度和生物量均在4月和8月呈现双峰值,砂壳纤毛虫丰度和生物量均在7月出现单峰值。周年砂壳纤毛虫丰度占纤毛虫总丰度的比例平均为(28.6±32.6)%,5-7月较高,均超过50%。共鉴定砂壳纤毛虫6属21种,其中拟铃虫属(Tintinnopsis)种类最多,6-8月砂壳纤毛虫种类数最高。砂壳纤毛虫种类组成呈现明显的周年变化,温度是驱动砂壳纤毛虫群落周年变化的主要环境因子。砂壳纤毛虫群落Shannon指数的平均值为0.95±0.78,Pielou指数的平均值为0.52±0.34,均在6-8月较高。除无壳纤毛虫外,砂壳纤毛虫丰度、纤毛虫总丰度和砂壳纤毛虫丰度占纤毛虫总丰度的比例均与温度、Chl a浓度呈显著的正相关,与盐度呈显著的负相关。 Abstract:To understand annual variation of abundance and biomass of planktonic ciliates in the Bohai Bay, ciliates were sampled monthly at a fixed station from July 2019 to June 2020. A 1-L sample of surface water was collected with a 2.5 L Niskin water sampler and fixed in 1% acid Lugol's iodine solution. Water samples were pre-concentrated using the Utermöhl method and observed under an Olympus IX71 inverted microscope at 100×or 400×magnification. The dimensions of the ciliates were measured and the cell volume of each species was estimated using appropriate geometric shapes. The carbon:volume ratio used to calculate biomass was 0.19 pg C/μm3. Aloricate ciliates were divided into three classes according to the size of cell volume. The classification of tintinnids was based on taxonomic literature. The average abundance of aloricate ciliates was (1382±1929) ind/L, ranging from 137 ind/L to 6748 ind/L. The average biomass of aloricate ciliates was (2.29±3.05) μg C/L, ranging from 0.09 μg C/L to 10.83 μg C/L. The average tintinnid abundance was (946±2384) ind/L, ranging from 0 ind/L to 8440 ind/L. The average tintinnid biomass was (3.86±11.57) μg C/L, ranging from 0.00 μg C/L to 40.57 μg C/L. The average abundance of total ciliates was (2328±2735) ind/L, ranging from 143 ind/L to 8577 ind/L. The average biomass of total ciliates was (6.15±11.35) μg C/L, ranging from 0.09 μg C/L to 41.02 μg C/L. Both abundance and biomass of aloricate ciliates and tintinnids showed strong annual variations throughout the year. Two peaks of aloricate ciliates were observed in April and August, respectively. Tintinnid abundance and biomass peaked in July. Tintinnids occupied (28.6±32.6)% of total ciliate abundance, being higher (>50%) from May to July. Twenty one tintinnid species were identified, 13 of which were in genus Tintinnopsis. The dominant species were Leprotintinnus simplex, Leprotintinnus nordqvisti and Tintinnidium primitivum. Species number of tintinnids showed higher level from June to August. Species composition of tintinnids exhibited obvious annual variation, and temperature was the main environmental factor driving the annual variation of tintinnid community. The average value of the Shannon index and Pielou index of tintinnid community were 0.95±0.78 and 0.52±0.34, respectively. Both Shannon index and Pielou index of tintinnid community were higher from June to August. There were not significant relationships between aloricate ciliate abundance and environmental factors. Tintinnid abundance, total ciliate abundance, and the percentage of tintinnids to total ciliate abundance were significantly positively correlated with temperature and Chl a concentration, while negatively correlated with salinity. 参考文献 相似文献 引证文献

Impact of the warm eddy on planktonic ciliate, with an emphasis on tintinnids as bioindicator species

Mesoscale eddies are a common feature of world oceans. However, their influence on microzooplankton has not been well studied. This study investigated the impact of warm eddies (originating from the Kuroshio Current) on planktonic ciliates in the northern South China Sea and the western North Pacific. We found more tintinnid species in warm eddies than in reference areas in both seas. All species categorized as abundant (maximum abundance > 5 ind. L−1 and occurrence frequency > 10%) could be divided into subsurface-peak and surface-peak groups (highest abundance appeared in subsurface and surface layers, respectively). Subsurface-peak tintinnid species vertical distribution together with temperature-salinity-plankton diagrams at each sampling points revealed higher abundance in warm eddies than in reference areas, which suggested that they can act as warm eddy bioindicator species. Surface-peak tintinnid species were mainly distributed in both warm eddy and reference areas, depth and temperature were the main influence factors. The vertical distribution in warm eddies showed a bimodal pattern in both the South China Sea and North Pacific, with abundance peaks in surface and subsurface layers; whereas in reference areas, abundance peaks in surface layers. The average abundance of ciliate and tintinnids in subsurface layers were higher in warm eddies than in reference areas. Our study contributed to a better understanding of the impact of the warm eddy on microzooplankton and tintinnids function as usefully bioindicator species. Further research is needed to fully understand the ecological influence of eddies on the microzooplankton community.

Tintinnids (Ciliophora, Oligotrichea) within power plant discharge and marine protected areas in Masinloc-Oyon Bay

There are only five studies on tintinnids of the Philippines. We present a checklist of tintinnids (Ciliophora, Oligotrichea) from Masinloc-Oyon Bay, Province of Zambales, West Philippine Sea. Masinloc-Oyon Bay is a unique in having both marine protected areas and a coal-fired thermal power plant within the same bay. Field sampling was performed in July 2017, which recorded 10 species belonging to one order, six families, and seven genera. Station 1 inside the power plant&amp;rsquo;s outfall had the lowest diversity, whereas the stations within marine protected areas had a relatively higher species diversity index. Our new data are the first records of tintinnid species in Masinloc-Oyon Bay. These records add to the regional checklist of the Philippine Sea.

Potential of a Tintinnid Species, Tintinnidium primitivum, as a Biological Indicator in the Yellow Sea Bottom Cold Water

Potential of a Tintinnid Species, Tintinnidium primitivum, as a Biological Indicator in the Yellow Sea Bottom Cold Water

A Novel Parasitic, Syndinean Dinoflagellate Euduboscquella triangula Infecting the Tintinnid Helicostomella longa

A tintinnid species, Helicostomella longa, infected by the parasitic dinoflagellate Euduboscquella triangula n. sp. was discovered from the southern coast of Korea in August of 2015 and 2016. Parasite morphology and development were analyzed by observation of live cells and protargol-stained specimens. The parasite was determined to be a new species in the genus Euduboscquella based on morphological and molecular data. A representative sequence of the novel species clustered in Euduboscquella group I. The morphological and developmental features of E. triangula were distinguished from those of its congeners by: (1) numerous shallow and intertwining grooves on an inconspicuous shield; (2) sporocytes initially forming a short chain, but separating after the second or third division regardless of spore type; (3) production of motile mushroom-shaped dinospores, non-motile spherical spores, and non-motile triangular spores. Dinospores were formed by ca. 28% of infections, while both non-motile spherical and triangular spores occurred at a frequency of ca. 36%. All spore types showed completely identical 18S rDNA sequences. Parasite prevalence was 15.5 and 8.3% on 17 and 24 August of 2015, respectively, with infection intensity on both dates being 1.3.