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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 exclusively 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. [ABSTRACT FROM AUTHOR]

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'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. [ABSTRACT FROM AUTHOR]

Se presenta el análisis de las variaciones estacionales de dinoflagelados tecados y tintínidos encontrados en cerca de 400 muestras de plancton recolectadas quincenalmente en seis estaciones fijas, durante 14 meses, en el Estero de Castro (Chiloé, Chile). Los resultados revelan una fuerte variación estacional de la diversidad específica y el número de células de cada especie, tanto en el interior como en el exterior, como se define en este artículo.

Here we summarize the results from 10 cruises in the Chukchi Sea, in August, each year from 2011 to 2020. Samples for the qualitative analysis of the microzooplankton were obtained from stations located across the Chukchi Sea using a 20µm plankton net. Conditions encountered, in terms of sea ice coverage and chlorophyll concentrations, varied widely from year to year without any obvious relationship with the composition of the microzooplankton assemblage. Examining a total of 242 samples gathered, we found a total of 44 tintinnid species (morphologically distinct forms). Plotting cumulative number of tintinnid species encountered vs cumulative number of samplings gave a typical species accumulation curve showing no sign of saturation suggesting that continued sampling in the Chukchi Sea will likely yield increases in the tintinnid species catalogue. The tintinnid species found ranged widely in lorica opening diameters (LOD) from about 11 µm to 80 µm in diameter. However, the median size of the LOD of the tintinnid assemblages varied little from year to year ranging only from about 30 µm to 40 µm. Most of the forms encountered were found in samples from only 1 or 2 cruises. Very few forms were found every year throughout the 10 years of sampling. These were 5 species of tintinnids (Acanthostomella norvegica, Leprotintinnus pellucidus, Pytchocylis obtusa, Salpingella acuminata, Salpingella faurei) and the nasselarian radiolarian Amphimelissa setosa. Examples of the morphological variability observed among individuals of Acanthostomella norvegica and Pytchocylis obtusa within single samples are shown with some individuals easily confused with forms described as other species are shown. To our knowledge, our data are the most extensive data set on Chukchi Sea microplankton. We provide all of the data recorded, which may serve as a baseline from which to assess changes projected in Arctic Sea systems, in a supplementary data file. [ABSTRACT FROM AUTHOR]

The deep sea has long been a mysterious and attractive habitat for protistologists. However, logistical difficulties severely limit sampling opportunities. Consequently, our knowledge of the protists in the deep sea, (arguably the largest habitat on earth), is relatively sparse. Here, we present a unique time‐series concerning three different protist taxa that share only the characteristics of being relatively large, robust to sampling, and easily identifiable to species level using light microscopy: tintinnid ciliates, phaeogromid cercozoans (e.g. Challengerids) and amphisolenid dinoflagellates. We sampled a near‐shore deep water site in the N.W. Mediterranean Sea at 250 m depth over a 2‐yr period at approximately weekly intervals from January 2017 to December 2018. To our knowledge, no previous studies have employed sampling on a similar time scale. We found taxa that appear to be restricted to deep waters, distinct seasonal patterns of abundance in some taxa, and in others nonseasonal successional patterns. Based on data from sampling following a flash flood event, the Challengerid population appeared to respond positively to a pulse of terrigenous input. Some of the distinct mesopelagic tintinnid ciliates and amphisolinid dinoflagellates were also found in two samples from the North Atlantic mesopelagic gathered from near the Azores Islands in September 2018. We conclude that there are a variety of protist taxa endemic to the mesopelagic, that the populations are dynamic, and they may be widely distributed in the deep waters of the world ocean. [ABSTRACT FROM AUTHOR]

Is there a mesopelagic protist fauna composed of species different from that of the overlying surface community? Does the mesopelagic community show seasonal changes in abundances and species composition? We addressed these questions by considering three distinct groups in which species identification is relatively unambiguous: tintinnid ciliates, phaeodarian radiolarians, and amphisolenid dinoflagellates. We sampled weekly at 250 m and 30 m depth from January to June a deep-water coastal site characterized by seasonal changes in water column structure; notably, in winter the mixed layer extends down into mesopelagic depths. We found a deep-water community of tintinnid ciliates comprised of forms apparently restricted to deep waters and species also found in the surface layer. This latter group was dominant during the winter mixis period when tintinnid concentrations were highest and subsequently declined with water column stratification. Phaeodarian radiolarians and the amphisolenid dinoflagellates were regularly found in deep samples but were largely absent from surface water samples and showed distinct patterns in the mesopelagic. Phaeodarian radiolarians declined with water column mixing and then increased in concentration with water column stratification whilst amphisolenid dinoflagellates concentrations showed no pattern but species composition varied. We conclude that for all three protists groups there appear to be both distinct mesopelagic forms and seasonal patterns. [ABSTRACT FROM AUTHOR]

Abundance and composition of the planktonic tintinnid ciliates were studied in the Gulf of Trieste (Northern Adriatic Sea, NE Mediterranean Sea) from July 1998 to July 2016. Tintinnids were collected biweekly-monthly from the LTER station C1 (200 m offshore, 17.5 m depth) at four depths (surface, 5 m, 10 m and 15 m). The maximum tintinnid abundance reached 4476 ind. L-1 at surface in February 2016. The tintinnid community comprised a maximum of 35 species and was dominated by the genera Stenosemella, Tintinnopsis, Codonellopsis, Salpingella and Eutintinnus. The most abundant species were Stenosemella nivalis, Tintinnopsis nana, Codonellopsis schabi, Salpingella rotundata and Eutintinnus apertus. We found a species-specific correlation with the abiotic factors considered, i.e., temperature and salinity. Temperature was positively correlated with S. rotundata and E. apertus and negatively with S. nivalis. Salinity was negatively correlated with the majority of the detected species. Agglutinated species presented winter maxima while hyaline species showed higher abundance in summer-autumn. Some key species were present over the whole period studied. Significant differences within the water column were not seen in the species composition, but were seen in the relative abundances of the same species at different depths. Stenosemella nivalis, S. ventricosa and Tintinnopsis beroidea can be considered as keystone species in the area and their possible loss can be seen as a signal of changes in the structure of the entire planktonic system. [ABSTRACT FROM AUTHOR]

Planktonic ciliates are important microzooplankton in pelagic ecosystems. Previous studies in Antarctic waters have only investigated ciliate assemblages in different habitats without considering water masses. In this article, we report the characteristics of ciliate assemblages in different water masses in open waters near Prydz Bay (East Antarctica) during austral summer. Three water masses were identified according to temperature and salinity: Summer Surface Water (SSW), Winter Water (WW), and Circumpolar Deep Water (CDW). SSW was further divided into SSWChl a < 3 (in vivo Chlorophyll a > 3 mg m−3) and SSWChl a < 3 (in vivo Chlorophyll a < 3 mg m−3). Ciliate abundance and biomass in water masses decreased in the order: SSW > WW > CDW. SSWChl a > 3 had a higher proportion (38.2%) of tintinnids to the total ciliate abundance and larger aloricate ciliates (ciliates in the 10-20 µm size class were < 15% of the total aloricate ciliate abundance) than in other water masses. WW had a higher proportion (> 30%) of Southern Ocean endemic tintinnid species in total tintinnid abundance than in other water masses. Each water mass had the following indigenous tintinnid species: SSW, Salpingella sp., Codonellopsis gaussi; WW, Salpingella costata, S. faurei, Cymatocylis affinis/convallaria forma drygalskii, and C. vanhoeffeni. Laackmanniella naviculaefera and C. affinis/convallaria forma cristallina were present at high abundance in both WW and SSWChl a > 3. Upwelling caused discontinuity of the ciliate distribution. Our results will help predict the spatial and temporal variations of ciliate assemblages and other plankton according to the dynamics of water masses in Antarctic waters. [ABSTRACT FROM AUTHOR]

Copyright of Ege Journal of Fisheries & Aquatic Sciences (EgeJFAS) / Su Ürünleri Dergisi is the property of Ege Journal of Fisheries & Aquatic Sciences (EgeJFAS) / Su Urunleri Dergisi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Much has been written on annual variation of tintinnid assemblages although the mechanism causing the annual variation has been poorly studied either in form of species richness or Lorica Oral Diameter (LOD) size-classes. In the present study, a 10-year (May 2003 to December 2012) survey on species occurrence, abundance, and LOD variation of the tintinnid ciliates was conducted in Jiaozhou Bay, western Pacific. In contrast to previous studies, we found summer peaks in tintinnid species richness in Jiaozhou Bay validated by multi-year investigations. We studied phenology of every tintinnid species and explored the mechanism causing the annual variation. The hypothesis was that tintinnid species richness has a winter baseline, to which warm water species added with the progress of the season. We defined the occurrence types of each species, and found there was only one cold occurrence type species. There was no overlap of cold occurrence type and warm occurrence type in the transitional period between winter and summer. The second aim of this study was to explore annual variations in tintinnid assemblages in form of LOD and redundant species. The species frequency distribution patterns among LOD size-classes were similar all year round. The abundance frequency distribution pattern in LOD size-classes could be divided into two phases: cold phase and warm phase with exception of May and September. The portion of redundant species was about 50% in every month. Our result help understand and predict annual variation of tintinnid assemblages in terms of species richness and LOD in world oceans. [ABSTRACT FROM AUTHOR]

Abstract: A tintinnid ciliate isolated from waters of the Thames River (Connecticut, USA) is described through combined in vivo observation, protargol impregnation, and phylogenetic analysis. The novel genus Dartintinnus and its type species, D. alderae are distinct from established tintinnid taxa by a lorica that collapses on both anterior and posterior ends. Dartintinnus is placed in the family Eutintinnidae based on a hyaline, elongated lorica opened at both ends, a ciliary pattern including a ventral kinety, at least one dorsal kinety, and right, left and lateral fields, and a sister relationship with Eutintinnus in gene trees. Main differences between D. alderae and Eutintinnus species include a 5.5–6.5% divergence in the small subunit rRNA gene, the geometry of the lorica (resembling an isosceles tetrahedron when collapsed vs. a cylinder, respectively), the number of macronuclear nodules (two vs. four), and the number of dorsal kineties (one vs. usually two). Considering the features of the new genus, we improve the diagnosis of the family Eutintinnidae, including the presence of a lateral ciliary field that had been overlooked in some Eutintinnus species. This work exemplifies the potential for novel diversity, even in these relatively well‐studied protists, and the importance of an integrated approach for the description of tintinnid taxa. [ABSTRACT FROM AUTHOR]

The human activities generate inputs of pollutants that exacerbate the natural tendency to eutrophication in estuaries. The goal of this study was to investigate the effects of anthropogenic pollution on tintinnid assemblages along the coast of the Río de la Plata Estuary. Our working hypothesis was that the abundance and size structure of tintinnid assemblages are significantly modified by the availability of differently sized food items due the organic pollution and eutrophication. Results showed that a high degree of water quality deterioration was negatively correlated with tintinnid abundance and diversity. Consequently, sites where the concentration of nutrients was still high showed the highest representation of tintinnids with small lorica oral diameter (LOD), especially Tintinnidium balechi, associated with small-sized prey (bacteria, pico-, and nanophytoplankton). Finally, diversity index was maximum at sites where water was less polluted and T. balechi dominance alternates with species with a larger LOD, a phenomenon which is related to the increased size of the available food (microphytoplankton). These results suggest that tintinnid species composition and distribution represent useful predictors of water quality. [ABSTRACT FROM AUTHOR]

The paper reports an unusual response of the microzooplankton community to oceanographic conditions observed during the winter of 2015 in the open southern Adriatic. Record-breaking nauplii abundance of 13,734 ind. m-3 was sampled for the open southern Adriatic by 50-μm net sampling. This could be explained by (i) warmer-than-usual surface and intermediate ocean temperatures, (ii) higher precipitation that freshened and widened the surface layer, pushing saline Levantine Intermediate Water below a 400-m depth, and (iii) strong wind episodes that transported nutrients from the coastal zone to the open ocean and induced limited vertical mixing. Neritic tintinnids and viable photoautotrophs well below the photic zone support the last possibility. Average seasonal maximum of zooplankton abundance was shifted from spring and early summer to the late winter months. Our results document large and fast variations in production conditions rarely found to occur in oligotrophic waters such as the southern Adriatic Sea. [ABSTRACT FROM AUTHOR]

Assemblages of dinoflagellate cysts in lakebed sediments across the deep, meromictic basin of Sluice Pond (Lynn, Massachusetts) were compared with measurements of water quality and sediment geochemistry and with testate amoeba and tintinnid assemblages. Lakebed sediments below oxygenated waters (DO >2 mg/L) contain diverse testate amoebae, but sparsePeridinium willei-dominated dinoflagellate cyst assemblages. Sediments collected under hypoxic conditions (DO < 2 mg/L) showed higher preservation of organic carbon and nitrogen, and these deep basin sediments are characterised by diverse dinoflagellate cyst assemblages, but sieved microfossil assemblages are typically dominated by the planktonicCodonella crateraand the pseudo-planktonicCucurbitella tricuspis. Strong inverse relationships of cysts ofPeridinium willei(R2= 0.81) andDifflugia oblongatests (R2= 0.7) with water depth are attributed to variations in bottom water oxygen concentrations. Both ecological and taphonomic factors must be considered when reconstructing palaeoenvironments from microfossil assemblages. [ABSTRACT FROM AUTHOR]

Tintinnid ciliates are an important link in marine food webs as they feed on phytoplankton and bacteria while providing nutrients to higher trophic levels. Tintinnids are known to agglutinate mineral particles or dead biogenic material such as diatom frustules to their shell-like housing (lorica), however, reasons for this agglutination remain questioned. We report on our observation of agglomeration of the living diatoms Fragilariopsis curta, F. cylindrus, F. pseudonana and F. rhombica to loricae of the Antarctic tintinnid ciliates Laackmanniella naviculaefera and Codonellopsis gaussi. These unusual associations between living diatoms and tintinnids were exclusively observed south of 63.59°S. We discuss the significance of our new finding and generate hypotheses to be tested by future research. It remains unclear where these living diatom-tintinnid associations are initially formed (in or near sea ice or also further north when abundances of L. naviculaefera, C. gaussi, F. curta, F. cylindrus, F. pseudonana and F. rhombica happen to be relatively high); who the beneficiary is in this association; what the exact benefits are; and how they might influence the Southern Ocean carbon cycle. Nevertheless, our observation provides a key step forward towards illuminating the largely unknown ecology of two Southern Ocean-endemic tintinnid species. [ABSTRACT FROM AUTHOR]

Species identifications of tintinnid ciliates are based on characteristics of the lorica housing the ciliate cell. Molecular characterization of tintinnid ciliates has revealed the occurrence of cryptic species, genetically distinct forms with similar loricas, as well as polymorphic species in which genetically identical forms have distinct loricas. Among this latter category may be forms currently recognized as species of the genus Salpingacantha, erected by Kofoid and Campbell for forms originally described as varieties of species of Salpingella with 'teeth' on the margin of the lorica oral opening. Some workers have expressed the opinion that the genus is artificial and notably a recent molecular study suggested that Salpingella and Salpingacantha are likely synonyms. In this short communication we report on finding morphologically distinct loricas (containing ciliate cells) of Salpingacantha in single samples from stations in the North Pacific and Arctic Oceans in 2010, 2015 and 2016. We found up to 5 distinct Salpingacantha forms co-occurring, often with abundant Salpingella acuminata populations suggesting that some Salpingacantha species may be varieties of Salpingella acuminata. While we lack genetic data needed for definitive proof of polymorphism, here we document remarkable gradual gradients in morphology suggestive of polymorphism. [ABSTRACT FROM AUTHOR]

We set out to examine a postulated latitudinal trend in species richness within the Arctic Ocean. We compiled species records of tintinnid ciliates in the Arctic from the literature and added our own unpublished Chukchi Sea data to produce a database (available as an Online Resource data file) consisting of 1427 records of 89 species from 414 locations above 65°N sampled from 1885 to 2015. While there was no trend of species richness throughout the Arctic, there was a significant positive relationship between species richness and the number of sites sampled in a 2° band, suggesting a sampling effect. Plotting cumulative numbers of species and cumulative number of sites sampled by year, we found a linear relationship in log cumulative numbers of species and log sites sampled, and a lack of a plateau in the species accumulation trend. Species records are highly dominated by four species, accounting for 45% of the records: Acanthostomella norvegica, Parafavella denticulata, Ptychocylis obtusa and Salpingella acuminata, all of which, except S. acuminata, have long been suspected to be morphologically variable, with different morphotypes given undue species status. Pooling all reported species of Acanthostomella, Parafavella and Ptychocylis yielded little qualitative differences but considerable quantitative differences. We found large discrepancies in geographic coverage. We conclude that many zones projected to experience large changes in sea ice coverage are under-sampled. Based on the historical trend, the list of Arctic tintinnid ciliate species will likely continue to grow with new sampling, regardless of changes in the Arctic Seas. [ABSTRACT FROM AUTHOR]

To improve understanding of diversity, phylogeny and evolution in tintinnid ciliates, it is essential to link multiple molecular markers with properly identified and documented morphospecies. Accordingly, 54 tintinnid morphospecies/isolates mainly from the Yellow and East China Seas were collected and analysed. Using single-cell approaches, sequences were obtained for three rDNA loci (18S, ITS1-5.8S-ITS2, D1-D5 region of 28S). Twenty-six tintinnid morphospecies (29 isolates) are documented by micrographs, measurements, morphologically described, and compared with the original species description. Three rDNA loci-based phylogenetic analyses were then performed for these identified isolates. Sequences from 25 unidentified species/isolates were also included in the comparison of the three rDNA loci. Ribosomal DNA genes of the genus Leprotintinnus were analysed for the first time, showing that Leprotintinnus was closely related to Tintinnopsis radix and branched distinctly apart from the family Tintinnidiidae. Four novel clades (VI to IX) of the Tintinnopsis complex emerged in the 18S genealogies. Analyses of the relative variability in the ITS and 28S regions vs. the 18S rDNA showed that the ITS1-5.8S-ITS2 and ITS2 regions well co-varied with the 18S rDNA when the variations of the latter were less than 3%, whereas at difference of less than 1%, no correlation was found between the compared loci. These findings highlight the difficulties in using variable locus-based cut-off divergences in circumscribing tintinnid morphospecies. [ABSTRACT FROM AUTHOR]

In this study we investigate for the first time the zooplankton assemblages in a relatively small tidal channel called Bahía del Medio, situated in the middle-outer area of the Bahía Blanca Estuary, South of the Main channel. We focused the study on micro- and mesozooplankton assemblages with emphasis on tintinnids, copepods and meroplankton along the annual cycle 1997-1998. Fifteen species of tintinnids belonging to 6 genera were observed in the study area, the mean total tintinnid abundance fluctuating between 3.4 x 10(6) ind. m-3 and 5.1 x 10(6) ind m-3. The mesozooplankton comprised 11 taxa, total abundance fluctuating between 449 ind m-3 in March 1997 and only 1 ind m-3 in October 1997. The channel proved to be spatially homogeneous in its physical and biochemical features. Micro- and mesozooplankton abundance displayed a high degree of spatial homogeneity, though the seasonal variation in both environment and zooplankton was significant. Comparison with the zooplankton observed at a station in the Main channel of the estuary showed differences in number of taxa represented, a general lower abundance of both assemblages and the presence of some rare species, a fact which is discussed.Neste estudo pesquisamos pela primeira vez as associações do zooplâncton num pequeno canal de maré, relativamente novo e chamado Bahía del Medio, localizado na região média-exterior do estuário da Bahía Blanca e ao sul do canal principal. Focalizamos o estudo no micro- e mesozooplâncton com ênfase nos grupos Tintinnida, Copepoda e meroplâncton, ao longo do ciclo anual 1997-1998. Foram observadas 15 espécies de Tintinnida pertencentes a 6 gêneros; a abundância média total de Tintinnida variou entre 3,4 x 10(6) ind. m-3 e 5,1 x 10(6) ind. m-3. O mesozooplâncton apresentou 11 taxa e uma abundância total entre 449 ind. m-3 em março de1997 e 1 ind. m-3 em outubro de 1997. O canal provou ser espacialmente homogêneo em suas características biológicas, químicas e físicas. A abundância do micro- e mesozooplâncton mostrou um alto grau de homogeneidade espacial, embora a variaçao estacional fosse significativa nas características do meio ambiente e do zooplâncton. A comparação com o zooplâncton observado em uma estação de amostragem no canal principal do estuário mostrou diferenças no número de taxa, na abundância, em geral mais baixa, e na presença de algumas espécies raras , fato esse comentado.

In the Bay of Villefranche, tintinnid ciliates have been studied since 1879 yielding a unique time series. The species inventory, excluding likely synonymous records, numbers 108. Temporal increases in the inventory appear linearly related to sampling effort up until the 2000s with a cumulative sampling effort of about 200 dates. Subsequently, with a large increase in sampling to currently over 460 dates, the rate of increases in species numbers declines. Surprisingly, the inventory is not highly inflated by unique occurrences, as species found but once are only 17 out of the 108. However, in recent years many previously recorded taxa have not been seen. Missing from a species list derived solely from intensive sampling from 2013 to 2016 are 38 previously recorded species. Most (26 out of 38) were recorded from a single year and thus may have been temporary residents. However, 12 species were found in multiple years by different investigators suggesting relatively common occurrence in the past. The substantial effort required to adequately sample a locality and possible historical changes in species inventories suggest that claims of a species as ‘new’ to a locality should be made with caution & caveats. [ABSTRACT FROM AUTHOR]

The feasibility of a potential bioindicator based on functional groups of microzooplankton tintinnids for bioassessments of water quality status was studied during southwest monsoon (June to September) along the coastal waters of Kalpakkam, India during 2012–2015. The work highlights the following features (1) tintinnid community composed of 28 species belonging to 11 genera and 9 families, revealed significant differences among the four study sites (2) maximum numerical abundance (2224 ± 90 ind. l − 1 ) and species diversity (H′ = 2.66) of tintinnid were recorded towards Bay of Bengal whereas minimum abundance (720 ± 35 ind. l − 1 ) and diversity (H′ = 1.74) were encountered in the backwater sites, (3) multivariate analyses [RELATE, Biota-environment (BIOENV) and canonical analysis of principal coordinates (CAP)] reveal that chl a , nitrate and phosphate were the potential causative factors for tintinnid distribution. Based on the results, we suggest that tintinnids may be used as a potential bioindicator of water quality status in marine ecosystem. [ABSTRACT FROM AUTHOR]

Species determination is crucial in biodiversity research. In tintinnids, identification is based almost exclusively on the lorica, despite its frequent intraspecific variability and interspecific similarity. We suggest updated procedures for identification and, depending on the aim of the study, further steps to obtain morphological, molecular, and ecological data. Our goal is to help improving the collection of information (e.g. species re-/descriptions and DNA barcodes) that is essential for generating a natural tintinnid classification and a reliable reference for environmental surveys. These suggestions are broadly useful for protistologists because they exemplify data integration, quality/effort compromise, and the need for scientific collaborations. [ABSTRACT FROM AUTHOR]

The view that current species inventories (lists of binomial species) of planktonic protists significantly underestimate true diversity is widespread. However, the existence of synonyms in species lists, due to repeated descriptions of the same form, and polymorphism in which different "forms" or life-history stages are but one species, are generally underappreciated. Recent studies have shown that synonyms are probably common, significantly inflating species lists, and taxa previously thought to be distinct species based on morphology have been revealed to be simple variants of single species. Given here are examples from among tintinnid ciliates, dinoflagellates and foraminifera. The commonality of synonyms and the phenomena of both polymorphism and crypticism underscore a need for taxonomic reviews as well as speciesfocused studies involving molecular biologists, taxonomists and ecologists. [ABSTRACT FROM AUTHOR]

We present continuous bi-weekly to bi-monthly dinoflagellate cyst, tintinnid loricae and tintinnid cyst fluxes at two mooring sites in Hudson Bay (subarctic Canada) from October 2005 to September 2006. The total dinoflagellate cyst fluxes at the site on the western side of the bay ranged from 4600 to 53,600 cysts m − 2 day − 1 (average 20,000 cysts m − 2 day − 1 ), while on average three times higher fluxes (average 62,300 cysts m − 2 day − 1 ) were recorded at the site on the eastern side of the bay with a range from 2700 to 394,800 cysts m − 2 day − 1 . These values are equivalent to the average fluxes calculated from the top 1-cm sediment layer of 210Pb-dated box cores at corresponding locations, and hence lend support to the use of sediment dinoflagellate cysts in palaeoceanography. Tintinnid fluxes ranged from 1200 to 80,000 specimens m − 2 day − 1 (average 32,100 tintinnids m − 2 day − 1 ) in the west, and 1600 to 1,240,800 specimens m − 2 day − 1 (average 106,800 tintinnids m − 2 day − 1 ) in the east, with the highest Salpingella sp. fluxes recorded during the sea-ice cover season. The dinoflagellate cyst species diversity recorded in the traps was similar at the two environmentally differing locations, with cold-water (e.g., Echinidinium karaense , Islandinium minutum , Islandinium ? cezare , Polykrikos sp. var. arctica, Spiniferites elongatus ), cosmopolitan (e.g., Operculodinium centrocarpum , Spiniferites ramosus , Brigantedinium ) and typical warmer-water (e.g., Echinidinium aculeatum , Islanidium brevispinosum ) species present. Furthermore, the species-specific timing of cyst production behaved similarly relative to the seasonal sea-ice cycle at both locations. Cyst species proportions and species-specific flux quantities, however, differed between the two sites and corresponded to the quantities and species assemblages recorded in the surface sediment, with the exception of cysts of Polarella glacialis and cf. Biecheleria sp. that seem not to preserve well in sediment but were abundant in both traps. Otherwise, cyst assemblage at the western trap site was dominated by O . centrocarpum and S . elongatus while at the eastern site very high quantities of cysts of Pentapharsodinium dalei were recorded. Our data do not lend support to the hypothesis that trophic status solely determines whether cyst production takes place under-ice or in the open water, since cysts of light-dependent (phototrophic) and light-independent (heterotrophic) dinoflagellates are recorded during both conditions. Most importantly, negligible under-ice cyst production is recorded during the deep arctic winter. [ABSTRACT FROM AUTHOR]

Tintinnids are planktonic ciliates that play an important role in marine ecosystem. According to their distribution in the world oceans, tintinnid genera were divided into several biogeographical types such as boreal, warm water, austral and neritic. Therefore, the oceanic tintinnid assemblage could be correspondingly divided into boreal assemblage, warm water assemblage and austral assemblage. The purpose of this study was to investigate the characteristics of boreal tintinnid assemblage in the Northwest Pacific and the Arctic, and to identify the connection between boreal tintinnid assemblage and neighboring assemblages. Surface water samples were collected along a transect from the East China Sea to the Chukchi Sea in summer 2014. According to the presence of boreal genera and warm water genera, three tintinnid assemblages (the East China Sea neritic assemblage, the Japan Sea warm water assemblage, and the boreal assemblage) were identified along the transect. The boreal assemblage extended from the Chukchi Sea to the waters north of the Sōya Strait. Densities peaks occurred at stations in the two branches of the Alaska Current and decreased both northward and southward. The densities were <10 ind./dm3 at most stations in Arctic region. The dominant genera (Acanthostomella, Codonellopsis, Parafavella, and Ptychocylis) accounted for 79.07±29.67% (n = 49) of the abundance in the boreal assemblage. The densities of the dominant genera covaried with strongly significant positive correlations. Tintinnids with lorica oral diameter of 22–26 μm and 38–42 μm were dominant and contributed 67.35% and 15.13%, respectively, to the total abundance in the boreal assemblage. The distribution and densities of tintinnids in the study area suggest that the Sōya Strait might be a geographical barrier for tintinnids expansion. [ABSTRACT FROM AUTHOR]

Marine planktonic ciliates are important components of microzooplankton. Depending on the presence or absence of lorica, planktonic ciliates can be divided into tintinnids and aloricate ciliates. We hypothesize that the ecological distributions of the two groups were different due to their difference in morphology. To test this hypothesis, the spatial distribution of ciliates was studied in spring, summer and autumn 2011 in the East China Sea, a large marginal sea significantly affected by freshwater discharge. We found that tintinnids and aloricate ciliates had different vertical distributions. Tintinnids were distributed mainly near the bottom waters, while higher abundance of aloricate ciliate was found in waters 30–70 m above the bottom. The contribution of tintinnids to the total ciliate abundance decreased with increasing distance from the bottom. In waters with distance from the bottom > 80 m, tintinnids accounted for < 10% of the total ciliate abundance. The Changjiang River discharge in summer enhanced aloricate ciliate abundance compared with spring and autumn, although tintinnid abundance did not change significantly. Tintinnidium primitivum was the dominant tintinnid near the bottom waters. Our study clearly showed that aloricate ciliates and tintinnids had different vertical distributions and responses to freshwater discharge in the East China Sea. [ABSTRACT FROM AUTHOR]

Tintinnid are important microzooplankton in marine pelagic habitats. In the temperate shelf area, tintinnid could be divided into neritic, warm-water and cosmopolitan biogeographical types. Up to now, there is no understanding in the interaction between neritic and warm-water genera in shelf waters. Here we studied the interaction of neritic and warm-water tintinnids in East China Sea during three cruises (May, August and October) in 2013. Our hypothesis were (1) that the factors influencing the expansion of neritic and warm-water genera were different and (2) that different genera within each biogeographical type had different adaptation abilities in the process of expansion. Totally 94 species in 36 genera were identified in three cruises. According to the distribution of each tintinnid genus in the three cruises, tintinnid genera were divided into three biogeographical types: neritic, warm-water and cosmopolitan. The data confirmed our hypothesis. The factor influencing neritic tintinnid species richness and abundance was water depth while salinity was the factor influencing species richness and abundance of warm-water tintinnids. According to the difference in their expansion ability, neritic and warm-water genera could be divided into core genera and pioneer genera. In the case of neritic genera, core and pioneer neritic genera stayed together in May and August while pioneer neritic genera expanded a lot out to the oceanic water in October. In the case of warm-water genera, the pioneer genera always expanded a lot out to the coast in all three cruises. In May and August, the pioneers of neritic and warm-water genera did not meet. However, in October, the cores of neritic and warm-water genera collided. Our data clearly showed that the core and pioneer of both neritic and warm-water genera interacted in different modes in different months. Whether the cores of neritic and warm-water genera will further mixed in winter is an open question. [ABSTRACT FROM AUTHOR]

The syndinean dinoflagellate Euduboscquella costata n. sp., an intracellular parasite of the tintinnid ciliate Schmidingerella arcuata, was discovered from Korean coastal water in November of 2013. Euduboscquella costata parasitized in about 62% of the host population, with infection intensity (= number of trophonts in a single host cell) ranging from 1 to 8. Based on morphology and nuclear 18S ribosomal RNA gene sequences, the parasite is new to science. Euduboscquella costata n. sp. had an infection cycle typical of the genus, but had morphological and developmental features that distinguished it from congeneric species. These features include: (1) episome of the trophont with 25-40 grooves converging toward the center of the shield; (2) a narrow, funnel-shaped lamina pharyngea extending from the margin of the episomal shield to the nucleus; (3) persistence of grooves during extracellular development (sporogenesis); (4) a single food vacuole during sporogenesis; (5) separation of sporocytes early in sporogenesis, regardless of type of spore formed; and (6) dinospore size (ca. 14 μm in length) and shape (bulbous episome with narrower, tapering hyposome). After sporogenesis, E. costata produced four different types of spore that showed completely identical 18S rRNA gene sequences. The gene sequence was completely identical with a previously reported population, Euduboscquella sp. ex S. arcuata, from Assawoman Bay, USA, indicating that the two populations are likely conspecific. Favella ehrenbergii, a widely recorded tintinnid known to host Euduboscquella spp., co-occurred with S. arcuata, but was not infected by E. costata in field samples or during short-term, cross-infection experiments. [ABSTRACT FROM AUTHOR]

Ciliated protozoa have many advantages in bioassessment of water quality. The ability of tintinnids for assessing water quality status was studied during a 7-year cycle in Jiaozhou Bay of the Yellow Sea, northern China. The samples were collected monthly at four sites with a spatial gradient of environmental pollution. Environmental variables, e.g., temperature, salinity, chlorophyll a (Chl a ), dissolved inorganic nitrogen, soluble reactive phosphate (SRP), and soluble active silicate (SRSi), were measured synchronously for comparison with biotic parameters. Results showed that: (1) tintinnid community structures represented significant differences among the four sampling sites; (2) spatial patterns of the tintinnid communities were significantly correlated with environmental variables, especially SRSi and nutrients; and (3) the community structural parameters and the five dominant species were significantly correlated with SRSi and nutrients. We suggested that tintinnids may be used as a potential bioindicator for discriminating water quality status in marine ecosystems. [ABSTRACT FROM AUTHOR]

The present study gathers pioneering taxonomical and community data on testate amoebae and agglutinated tintinnids, analyzing their seasonal and spatial distribution patterns in the mesotidal system of the Guadiana Estuary, southeastern Portugal. To evaluate both groups’ potential as bioindicators in climate monitoring and paleoenvironmental reconstructions, their abundance, diversity and living proportions were compared to elevation in relation to mean sea-level, marine influence and to periods of elevated water levels. The distributions of testate amoebae and tintinnid total assemblages were also related to major physicochemical variables by means of multivariate analysis. From 49 surface sediment samples collected in winter and summer 2010, 17 species (25 strains) of testate amoebae were identified (in the 63 μm fraction). The Centropyxidae, mainly represented by Centropyxis aculeata , Centropyxis arcula and Centropyxis constricta , had the greatest density (71% of total individuals), while the Difflugidae represented the most species (82% of total species). Higher diversities and densities were observed in winter in the upper estuary, where salinity is negligible, and in the middle estuary where they are concentrated at the lower levels of the intertidal zone. Few or no individuals were observed in the highest marsh zones. In winter, dead testate amoebae were dominant, with empty tests accumulating in the sediments from post-mortem transport by high river discharge. In summer, an increase in the living fraction is observed, with living testate amoebae along the entire estuary, which could indicate that some species are able to live in the lower reaches of the estuary. Along with the testate amoebae, two species of agglutinated tintinnids (>63 μm), Stenosemella ventricosa and Tintinnopsis cf. lata , were abundant in the sediments. Their highest abundances were observed in summer. Living individuals were only recorded in summer, mainly in the vicinities of freshwater and sewage outflows, where elevated nutrient concentrations may be expected. The present study demonstrates that both testate amoebae and tintinnids have well defined patterns in their temporal and spatial distribution, offering high bioindicator potential in environmental/climate monitoring studies as well as in paleoenvironmental reconstructions. [ABSTRACT FROM AUTHOR]

This study focuses on the utility of molecular markers for the discrimination of closely related species in tintinnid ciliates. We analyzed the ecologically important genus Helicostomella by sequencing part of the large-subunit rDNA (LSU rDNA) and the 5.8S rDNA combined with the internally transcribed spacer regions 1 and 2 (5.8S rDNA-ITS) from forty-five individuals collected in NW and SW Atlantic waters and after culturing. Although all described Helicostomella species represent a continuum of morphologies, forms with shorter or longer loricae would correspond to different species according to previous molecular data. Here we observed that long forms show both crypticity (i.e. two almost identical long forms with different DNA sequences) and polymorphism (i.e. some long forms develop significantly shorter loricae after culturing). Reviewing all available tintinnid sequences, we found that 1) three Helicostomella clusters are consistent with different species from a molecular perspective, although these clusters are neither clearly differentiated by their loricae nor unambiguously linked to described species, 2) Helicostomella is closely related (probably to the family or genus level) to four “ Tintinnopsis -like” morphospecies, and 3) if considered separately, neither LSU rDNA nor 5.8S rDNA-ITS completely discriminate closely related species, thus supporting the use of multi-gene barcodes for tintinnids. [ABSTRACT FROM AUTHOR]

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Abundance, biomass, and taxonomic composition of the ciliate community were studied in the surface waters along a transect between 50°S 61°W and 48°N 5°W (Atlantic Ocean, March-April 2011). The abundance of heterotrophic ciliates was low in the equatorial zone (280-320 cells l, 0.11-0.12 μg C l), but it increased toward both the northern and southern temperate zones with the maximum abundance observed at 44°S (2667 cells l, 0.82 μg C l). This pattern resembles the global distribution of oceanic primary production, which is low at lower latitudes and high in temperate zones. In temperate zones ciliate abundance peaks during spring and fall. Thus, because the present study was carried out during spring in the northern hemisphere and austral fall in the southern hemisphere, the ciliate abundance at higher latitudes was additionally elevated. Functionally autotrophic Mesodinium rubrum was only observed in the northern hemisphere and tropical waters. Its maximum abundance was observed at 48°N (1080 cells l, 1.14 μg C l). The most frequently observed ciliates were oligotrichs and choreotrichs. Other important ciliates were haptorids (including M. rubrum) and hypotrichs. [ABSTRACT FROM AUTHOR]

On its route from the Mediterranean in the north to the Red Sea in the south, the Suez Canal crosses three different lakes which represent different habitats, and in some cases, hinder the migration of the fauna and flora from one sea to the other. Tintinnid species–specific abundance was determined at monthly intervals from 10 stations in the Suez Canal. A total of 18 species were recorded in the canal water, all Indo-Pacific in origin. Six of these species have been introduced to the Mediterranean, while 11 are new geographical records for the Suez Canal. Most species exhibited a seasonal cycle with low winter and high spring and summer densities. Tintinnid affinities and differences between the eastern Mediterranean and the Red Sea were discussed in the light of the results of distribution studies of the eighteen species of Tintinnid carried out over a complete year. These observations point to the role of the canal as a selective barrier and/or as a link in the migration of Tintinnid protozoa. While cases of migration from one sea to the other are more likely to occur in either direction, those concerning species of Indo-Pacific origin are more successful and numerous. Meanwhile, the Suez Canal acts as a local endemic habitat by itself. [ABSTRACT FROM PUBLISHER]

In this study, the spatial distribution and seasonal variation of large tintinnids (>76 μm) were investigated in Shenhu Bay during three seasons of 2012. Of the 36 species identified, 9 were dominant (i.e. Tintinnopsis radix, Leprotintinnus simplex, Tintinnopsis japonica, Tintinnopsis tubulosoides, Leprotintinnus nordqvisti, Tintinnopsis beroidea, Stenosemella parvicollis, Tintinnidium primitivum, Tintinnopsis nana). A clear seasonal shift of the taxonomic composition as well as the lorica size of the dominant species was observed. The highest numbers of tintinnid species occurred in spring, while the highest abundance and biomass occurred in summer. Clustering indicated that the seasonal variations of the community structure were more obvious than spatial variations. Spearman correlation analysis revealed that density of phytoplankton prey had a significant impact on the tintinnid abundance. Redundancy analysis (RDA) illustrated that temperature, salinity and the nutrient level were the most important abiotic factors affecting the spatial and seasonal pattern of tintinnid communities in Shenhu Bay. [ABSTRACT FROM AUTHOR]

In 2010, nearly 7 million liters of chemical dispersants, mainly Corexit® 9500A, were released in the Gulf of Mexico to treat the Deepwater Horizon oil spill. However, little is still known about the effects of Corexit 9500A and dispersed crude oil on microzooplankton despite the important roles of these planktonic organisms in marine ecosystems. We conducted laboratory experiments to determine the acute toxicity of Corexit 9500A, and physically and chemically dispersed Louisiana light sweet crude oil to marine microzooplankton (oligotrich ciliates, tintinnids and heterotrophic dinoflagellates). Our results indicate that Corexit 9500A is highly toxic to microzooplankton, particularly to small ciliates, and that the combination of dispersant with crude oil significantly increases the toxicity of crude oil to microzooplankton. The negative impact of crude oil and dispersant on microzooplankton may disrupt the transfer of energy from lower to higher trophic levels and change the structure and dynamics of marine planktonic communities. [Copyright &y& Elsevier]

The study is the first documentation of seasonal variations in species composition, abundance and diversity of tintinnid (Ciliata: Protozoa), in relation to water quality parameters along the stretch of the Hooghly (Ganges) River Estuary (HRE), eastern coastal part of India. A total of 26 species (22 agglomerated and 4 non-agglomerated) belonging to 8 genera has been identified from 8 study sites where Tintinnopsis (17 species) represented the most dominant genera, contributing up to 65 % of total tintinnid community followed by Tintinnidium (2 species), Leprotintinnus (2 species) and Dadayiella, Favella, Metacylis, Eutintinnus and Helicostomella (each with solitary species). The maximum (1,666 ind. l) and minimum (62 ind. l) abundance of tintinnids was recorded during post-monsoon and monsoon, respectively. A distinct seasonal dynamics in terms of biomass (0.005-2.465 μg C l) and daily production rate (0.04-3.13 μg C l day) was also noticed, accounting highest value during pre-monsoon. Chlorophyll a and nitrate were found to be potential causative factors for the seasonal variations of tintinnids as revealed by a stepwise multiple regression model. The result of ANOVA showed a significant variation between species abundance and months ( F = 2.36, P ≤ 0.05). k-dominance curves were plotted to determine the comparison of tintinnid dominance between the investigated stations. Based on a principal component analysis (PCA), three main groups were delineated with tintinnid ciliates and environmental parameters. The changes in lorica morphology in terms of temperature and salinity, recorded for three dominant species, provided information on the ecological characteristics of the species assemblage in this estuarine system. [ABSTRACT FROM AUTHOR]

Abstract: A Givetian palynological samples from the A1-69 borehole, Libya, yield intriguing palynomorphs vase shaped; and about 1500μm in length. They are tentatively compared with extant tintinnids. They could be the oldest organic lorica which may be related to tintinnids extracted from several Jurassic and Cretaceous pelagic limestone. [Copyright &y& Elsevier]

The Chukchi Sea was sampled in August of 2011, a year of near-normal sea ice among recent years, and again in August 2012, a year of all time record low sea ice. We exploited this sampling to test the hypothesis that different sea ice conditions are associated with differences in abundances or species composition of microzooplankton through an examination of tintinnids and radiolarians. From 18 stations in 2011, and 19 stations in 2012, organisms were enumerated in plankton net tow material, and chlorophyll determinations made (total and = 20 µm) from discrete depth samples. We found that the low sea ice conditions of 2012 were associated with higher chlorophyll concentrations (both total and the = 20 µm size fraction), compared to 2011. However, tintinnid ciliates and radiolarians were much lower in concentration, by about an order of magnitude, compared to 2011. In both years the radiolarian assemblage was dominated by Amphiselma setosa. The species composition of the tintinnid ciliates was similar in the two years, but there were distinct differences in the relative abundances of certain species. The 2012, low sea ice assemblage, was dominated by small forms in contrast to 2011, when large species were the most abundant. We present these fi ndings in detail and discuss possible explanations for the apparent differences in the microzooplankton communities associated with distinct sea ice conditions in the Chukchi Sea. [ABSTRACT FROM AUTHOR]

The species-rich order Tintinnida is a group of planktonic ciliates ubiquitous in coastal marine waters, which can be well described using molecular estimates of diversity. We studied temporal changes of tintinnid diversity over 1 year in a coastal Mediterranean Sea location (Villefranche-sur-Mer, France) at five different depths (5, 25, 50, 100, and 160 m) and one additional year at 50 m depth by combining denaturing gel gradient electrophoresis ( DGGE) community fingerprinting with direct PCR amplification, cloning and sequencing of small subunit ( SSU), 5.8S, and large-subunit ( LSU) rRNA genes together with the corresponding internal transcribed spacers ( ITS). We amplified tintinnid sequences in all samples. All identified phylotypes were closely related to described species, showing that there is a good phylogenetic reference sequence data set allowing accurate estimation of tintinnid diversity in these waters. Tintinnid community composition exhibited marked seasonal changes. Surprisingly, the tintinnid SSU rDNA-based species composition did not show any clear relationship to measured environmental parameters (temperature, salinity, light, phytoplankton biomass). Nonetheless, the comparison of tintinnid community composition using UniFrac revealed three significant clusters of sequences grouping, respectively, samples collected in winter, autumn, and summer, leading to the hypothesis that seasonal effects on tintinnid community composition might be related to biotic parameters. In addition, phylogenetic trees based on the concatenated SSU + LSU rDNA and ITS sequences showed a better resolution than SSU rDNA alone to discriminate closely related species. [ABSTRACT FROM AUTHOR]

Information of tintinnid community, as an important component of plankton, was limited in Kongsfjorden, Svalbard (Arctic), which is an important Arctic monitoring site for global change. In this paper, we studied the species composition, spatial, and vertical distribution of tintinnids in Kongsfjorden in July 2012. Water samples for tintinnid study were taken in different depths at eight grid stations in the fjord and time series (5-23 July) at one station at the pier (St. C). Eight species (morphotypes) were found: Acanthostomella norvegica, Leprotintinnus pellucidus, Parafavella edentata, Parafavella gigantea, Ptychocylis obtusa, Stenosemella spp., Tintinnopsis parvula, and Tintinnopsis spp. Total tintinnid abundance and biomass ranged from undetectable (<1 ind L) to 2,435 ind L and 0-6.33 μg C L, respectively. Cluster analysis of the tintinnid community in the grid stations and St. C showed that tintinnid community was uniform throughout the fjord. Four species (morphotypes) showed distinct vertical distributions: T. parvula occurred throughout the water column but showed a peak at the surface; Tintinnopsis spp. occurred only in the upper 30 m; A. norvegica occurred in low abundance throughout the water column; and Stenosemella spp. was not detected in surface waters. There was variation in abundance of different species in St. C in the 18-day period. However, the tintinnid community did not change according to cluster analysis. These results are helpful in understanding the distribution of other plankton taxon and in long-term monitoring of the Kongsfjorden marine ecosystem. [ABSTRACT FROM AUTHOR]

Tintinnid species are traditionally distinguished via lorica features. Recently, sequencing has revealed polymorphism, i.e., genetically identical individuals with distinct lorica morphologies. One such polymorphic species is Cyttarocylis ampulla; individuals can display lorica morphologies of formally different species of Cyttarocylis and Petalotricha, well-represented in the literature. We compiled and analysed a global database of species records to determine if there is a main form and if different morphotypes have distinct temporal or spatial distributions. The two genera show very similar widespread distributions but with some statistical evidence of spatial segregation. Examining co-occurrence among the common ‘species’ we found most were rarely found alone, only 6-14% of the records for all species except for 2 forms: C. eucecryphalus and P. ampulla reported alone in 34% and 43%, respectively, of their records. We identify them as the main forms and analysed data of global distributions, spatial distribution across the Mediterranean in summer and winter and temporal distributions from a site in the Adriatic. The two main forms show frequent co-occurrence, similar lack of strong seasonality and widespread geographic distributions. We tentatively conclude that the different lorica morphologies may only reflect conditions of high temporally variability such as quantities and composition of prey. Directions for further research are suggested. [ABSTRACT FROM AUTHOR]

We characterized six tintinnid ciliates from Antarctic waters using molecular markers and morphological traits: Amphorellopsis quinquealata, Codonellopsis gaussi, Cymatocylis convallaria, Cy. calyciformis, Cy. drygalskii, and Laackmanniella prolongata. The 100% similarity in SSU-ITS1-5.8S rDNA-ITS2-partial LSU rDNA sequences among Cy. convallaria, Cy. calyciformis, and Cy. drygalskii is supportive of synonymy. Codonellopsis gaussi and L. prolongata also showed high levels of similarity in SSU rDNA (99.83%) and the D2 domain of LSU rDNA (95.77%), suggesting that they are closely related. Phylogenetic analysis placed Cymatocylis in the Rhabdonellidae, Amphorellopsis in the Tintinnidae and L. prolongata/Co. gaussi within the Dictyocystidae. [ABSTRACT FROM AUTHOR]

Following the recent redescription of Rhizodomus tagatzi, we carried out a comprehensive study of the biogeography and ecology of this tintinnid ciliate based both on original data and a critical review of the literature. The data indicated that R. tagatzi is a neritic tintinnid ciliate, which has been reported, to date, only from the Northern Hemisphere at tropical to warm-temperate latitudes. It has most often been detected in estuaries or lagoons characterized by a high trophic level and stable water column, and typically in the seasonal periods of highest abundance of small-sized phytoplankton. The biogeographic pattern emerging from this study, along with the prevalence of this species in ports and in transition environments exploited for bivalve culture, confirms the former assumption of an invasive behaviour of R. tagatzi, and suggests aquaculture transplants as a possible means of dispersion for ciliated protozoa. [ABSTRACT FROM AUTHOR]

Many microbial taxa in the marine plankton appear super-saturated in species richness. Here, we provide a partial explanation by analyzing how species are organized, species packing, in terms of both taxonomy and morphology. We focused on a well-studied group, tintinnid ciliates of the microzooplankton, in which feeding ecology is closely linked to morphology. Populations in three distinct systems were examined: an Eastern Mediterranean Gyre, a Western Mediterranean Gyre and the California Current. We found that species abundance distributions exhibited the long-tailed, log distributions typical of most natural assemblages of microbial and other organisms. In contrast, grouping in oral size-classes, which corresponds with prey-size exploited, revealed a geometric distribution consistent with a dominant role of a single resource in structuring an assemblage. The number of species found in a particular oral size-class increases with the numerical importance of the size-class in the overall population. We suggest that high species diversity reflects the fact that accompanying each dominant species are many ecologically similar species, presumably able to replace the dominant species, at least with regard to the size of prey exploited. Such redundancy suggests that species diversity greatly exceeds ecological diversity in the plankton. [ABSTRACT FROM AUTHOR]

An intense monospecies bloom of the centric diatom Hemidiscus hardmannianus (Greville) Mann. (Bacillariophyceae) occurred in the coastal waters of Sundarban mangrove wetland, India on 22 July, 2010. The species was abruptly flourished (mean density 8.86 × 106 cells/L) resulting intense green coloration of water. The greatest impoverishment of diversity and density of phytoplankton, micro- and mesozooplankton community was observed during the bloom. The phytoplankton community showed an extreme reduction in diversity (12 species to one) and sharp decrease in standing stock (12.84 × 103 to 8.86 × 106 cells/L) during this period. The late bloom condition coincided with sudden and huge arrival of a clupoid fish Hilsa ilisha which forms the most potential fisheries in Sundarban deltaic region. An attempt has been made to correlate the satellite remote sensing-derived information to the bloom conditions. The MODIS-Aqua derived chlorophyll and TMI satellite derived sea surface temperature and wind speed maps have been interpreted. [ABSTRACT FROM AUTHOR]

Tintinnida is a diverse taxon that accommodates over 1,500 morphospecies, which is an important component of marine planktonic food webs. However, evolutionary relationships of tintinnids are poorly known because molecular data of most groups within this order are lacking. In our study, the small subunit ( SSU) rRNA genes representing 10 genera, 5 families of Tintinnida were sequenced, including the first SSU rRNA gene sequences for Coxliella, Dadayiella, Epiplocyloides, and Protorhabdonella, and phylogenetic trees were constructed to assess their intergeneric relationships. Phylogenies inferred from different methods showed that (1) Three newly sequenced Eutintinnus species fell into Eutintinnus clade forming a sister group to the clade containing Amphorides, Steenstrupiella, Amphorellopsis, and Salpingella; (2) Surprisingly, the genetic distances between Amphorides amphora and Amphorellopsis acuta population 1 was even smaller than that between the two populations of Amphorellopsis acuta, casting doubt on the validity of Amphorides and Amphorellopsis as presently defined; (3) The SSU rRNA sequences of Dadayiella ganymedes and Parundella aculeata were almost identical. Therefore, Parundella ganymedes novel combination is proposed; (4) Coxliella, which is currently assigned within Metacylididae, branched instead with some Tintinnopsis species. Furthermore, the validation of Coxliella, which was considered to be a 'questionable' genus, was confirmed based on evidences from morphology, ecology, and molecular data; (5) Protorhabdonella and Rhabdonella showed rather low intergeneric distance and grouped together with strong support suggesting that Rhabdonellidae is a well-defined taxon; and (6) Epiplocyloides branched with species in Cyttarocylididae indicating their close relationship. [ABSTRACT FROM AUTHOR]