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Wyświetlanie 1-12 z 12
Tytuł:
Inter-annual depth-dependent toxicity and bioaccumulation of cadmium in marine benthic protist communities
Autorzy:
Fernandez-Leborans, G.
Gabilondo, R.
Ruiz-Alvarez, S.
Powiązania:
https://bibliotekanauki.pl/articles/48324.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
biomass
cadmium toxicity
protist community
protist
toxicity
bioaccumulation
species number
benthic protist
density
Opis:
The toxicity and bioaccumulation of cadmium in a marine benthic protist community were examined at different depths within the sediment. For this purpose, sediment-water microcosms with 1000 μgCd dm−3 of the pollutant were used in two assays. The addition of cadmium caused a significant reduction in protist density, number of species and biomass. There was also a decrease in these three parameters with depth. During the treatment the density of protist groups was strongly depth-dependent. The dominant groups of protists at the different depths during the assay were also considered. The most dominant protist group in terms of density were the heterotrophic flagellates, both in the control and in the treatment with cadmium. In the treatments with cadmium, these were followed by ciliates and by dinoflagellates in both assays. In the control, all protist groups were present during the assay, whereas in the treatments with cadmium, autotrophic flagellates, diatoms and sarcodines were found in reduced proportion or not at all. Cadmium bioaccumulation increased towards the end of the assay. At any time during the assay, the proportion of cadmium bioaccumulated was an increasing function of depth.
Źródło:
Oceanologia; 2007, 49, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Taste and Smell in Acanthamoeba Feeding
Autorzy:
KHAN, Naveed Ahmed
IQBAL, Junaid
SIDDIQUI, Ruqaiyyah
Powiązania:
https://bibliotekanauki.pl/articles/763505.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Acanthamoeba, chemoreception, protist, model organism
Opis:
The ability to detect food in the environment is an essential function among all living organisms and must have arisen at the beginning of life. The anatomical, morphological and molecular features involved in taste and smell may differ among disparate groups, but the principle of chemoreception is conserved. Here we debate the sense of taste and smell in the feeding behaviour of the unicellular protist, Acanthamoeba.
Źródło:
Acta Protozoologica; 2014, 53, 2
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Micro- and Macroscale Changes in Density and Diversity of Testate Amoebae of Tropical Montane Rain Forests of Southern Ecuador
Autorzy:
Krashevska, Valentyna
Maraun, Mark
Scheu, Stefan
Powiązania:
https://bibliotekanauki.pl/articles/763597.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Altitude, epiphyte, live cells, moss, protist
Opis:
We investigated changes in diversity and density of testate amoebae in epiphytes of trees in tropical montane rain forests of southern Ecuador. Local – microscale [height on tree trunk of 0 (base of tree trunk), 1 and 2 m; TH I, TH II and TH III, respectively] and regional – macroscale (forests at 1000, 2000 and 3000 m) changes were investigated. At the macroscale diversity and density of testate amoebae peaked at 2000 m. At the microscale diversity reached a maximum at TH I, whereas density reached a maximum at TH III. The percentage of empty shells at the macroscale was at a maximum at 2000 m and at the microscale at TH I, whereas the percentage of live cells was at a maximum at 3000 m and at TH III. The diversity of testate amoebae in epiphytes found in the present study was high (113 species). However, only two to nine species were dominant representing 54–85 percent of total living testate amoebae. The results suggest significant variations in density and diversity of testate amoebae at both the micro- and macroscale. However, for testate amoebae density the macroscale appears most important whereas changes in diversity are more pronounced at the microscale
Źródło:
Acta Protozoologica; 2010, 49, 1
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nebela kivuense Gauthier-Lièvre et Thomas, 1961 (Amoebozoa, Arcellinida), Missing for a Half-century; Found 11,500 km from “home”
Autorzy:
Nicholls, Kenneth H.
Powiązania:
https://bibliotekanauki.pl/articles/763752.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Nebela, testate amoeba, Hyalospheniidae, protist biogeography
Opis:
In 1961, the testate amoeba Nebela kivuense Gauthier-Lièvre et Thomas, 1961 was described for the first and only time from an area near Lake Edward in the Democratic Republic of the Congo (at 0.002° N Latitude). The lack of recent reports of this species, despite exhaustive surveys of the testate amoebae fauna of the major continents of the world, suggested that N. kivuense was a rare species perhaps endemic to a small, local equatorial region of the African continent. This paper reports its rediscovery from two wetland-conifer forest ecosystems in southern Ontario, Canada (at 44° N Latitude), thus changing dramatically our previous perception of its very restricted global distribution. This has implications for the idea held by many students of biogeography that there is a special category of microscopic protists that contains truly rare species and their rarity, perhaps together with specific habitat requirements and tolerances, limits opportunities for dispersal around the world. The N. kivuense story is a clear example of the dangers of inferring endemism from rarity.
Źródło:
Acta Protozoologica; 2015, 54, 4
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structure of Organic Spines in the Rhizarian Protist Belonocystis tubistella Rainer, 1968, and a Description of Belonocystis quadrangularis n. sp. (Cercozoa, Insertae Sedis)
Autorzy:
Nicholls, Kenneth H.
Powiązania:
https://bibliotekanauki.pl/articles/942499.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Clathrulinidae, Desmothoracida, Rhizaria, pseudoheliozoa, spined protist
Opis:
Several Ontario (Canada) populations of the “heliozoan-like” protist Belonocystis Rainer, 1968 were studied to help elucidate the taxonomic position of this genus relative to other rhizarian protists with fine pseudopodia. The Ontario material presently includes two distinct species – B. tubistella Rainer and B. quadrangularis n. sp., described here as a new species based on cell morphology and microstructure of the spiny investiture encasing its cell. The organic nature of the spiny structures of both species has been confirmed by their dissolution in 6% sodium hypochlorite solution. Median cell diameters of B. tubistella and B. quadrangularis were 10.5 μm and 7 μm, respectively. As revealed by transmission electron microscopy, the spine bases in B. tubistella consisted of a complex structure of four curved ribs interconnected by a membranous sheet replete with closely-appressed, large circular to elliptical pores, while in B. quadrangularis the spine bases consisted of a simple four-cornered “pyramid” of struts that supported the main shaft of the spine. These findings strengthen the status of the genus Belonocystis and it placement outside the realm of the Centrohelida and Rotosphaerida.
Źródło:
Acta Protozoologica; 2012, 51, 1
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A New Species of Flamella (Amoebozoa, Variosea, Gracilipodida) Isolated from a Freshwater Pool in Southern Mississippi, USA
Autorzy:
Walthall, Austin C.
Brown, Matthew W.
Tice, Alexander K.
Powiązania:
https://bibliotekanauki.pl/articles/763591.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Amoeboid, amoeba, SSU rDNA, taxonomy, protist, phylogenetics, Flamella, Gracilipoida
Opis:
We isolated and identified a freshwater amoebozoan species that belongs to the genus Flamella Schaeffer, 1926 by single cell isolation and light microscopy. Our specific strain was isolated from a water sample obtained on the cover of a swimming pool in Petal, Mississippi, USA collected during the winter of 2015. Morphologically, our isolate is a fan-shaped amoeba with a large, frontal hyaloplasm and distinctive granuloplasm. It is capable of encystment and trophozoites occasionally have two nuclei. The isolate (GFP151sc) is phylogenetically sister to but unique from the freshwater environmental flamellid clone from Borok, Yaroslavl region, Russia originally published in 2006. Here we describe and place this isolate into a new species, Flamella piscinae n. sp.
Źródło:
Acta Protozoologica; 2016, 55, 2
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Genetic diversity of Blastocystis spp. in the human population of the Olsztyn area
Autorzy:
Lepczynska, M.
Dzika, E.
Stensvold, C.R.
Powiązania:
https://bibliotekanauki.pl/articles/5729.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Parazytologiczne
Tematy:
genetic diversity
Blastocystis
enteric protist
host
human population
Olsztyn region
Źródło:
Annals of Parasitology; 2016, 62, Suppl.
0043-5163
Pojawia się w:
Annals of Parasitology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zoelucasa sablensis n. gen. et n. sp. (Cercozoa, Incertae Sedis), a New Scale-covered Flagellate from Marine Sandy Shores
Autorzy:
Nicholls, Kenneth H.
Powiązania:
https://bibliotekanauki.pl/articles/763547.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Imbricatea (Silicofi losea), sand-dwelling protist, psammon, silica scales, flagellate
Opis:
Zoelucasa sablensis n. gen et n. sp. is a small heterotrophic fl agellate housed within a pyriform lorica of relatively large imbricate, circular siliceous scales. It was found in near-shore benthic sand/seawater samples of both the Pacific and Atlantic Oceans (west and east coasts of Canada; salinity = 32–33 ppt). The median length and width of the lorica was 18 and 11 μm, respectively (n = 29). This taxon lacks chloroplasts and swims with a slow zig-zag motion controlled by a short (5–7 μm long), anteriorly-directed flagellum and a longer trailing flagellum, 15–20 μm in length. Its classification within the phylum Cercozoa (most likely, Class Imbricatea) is tentative, as there are no known morphological homologues (discoidal, overlapping siliceous plate-scales forming a test or lorica enclosing a heterotrophic flagellate). Further study of cultured and wild material, including a search for other possible non-flagellate (e.g. amoeboid?) life history stages, TEM examination of cell sections, and rDNA sequencing will most certainly provide more opportunities for a justifi able classifi cation, possibly including a new Order.
Źródło:
Acta Protozoologica; 2012, 51, 2
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ultrastructure and SSU rDNA Phylogeny of Paraphysomonas vestita (Stokes) De Saedeleer Isolated from Laguna de Bay, Philippines
Autorzy:
Petronio, Joy Ann G.
Rivera, Windell L.
Powiązania:
https://bibliotekanauki.pl/articles/763493.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Paraphysomonas vestita, chrysophyte, protist, ultrastructure, small subunit ribosomal RNA gene, Philippines
Opis:
Paraphysomonas vestita is a unicellular, colorless, silica-scaled chrysophyte that plays an important ecological role in freshwater microbial communities as a consumer of prokaryotic and eukaryotic prey. There is little biogeographical information for this minute protist despite its significant role in aquatic food webs. In addition, the phylogenetic relationship of P. vestita to other taxa is unclear as P. vestita may be polyphyletic or a cryptic species complex. In this study, a clonal isolate from a freshwater sample of Laguna de Bay, Philippines was subjected to morphological study by electron microscopy and its small subunit ribosomal RNA (SSU rRNA) gene was sequenced. Morphological studies showed that the isolate possesses two unequal flagella emerging from the anterior part of the cell. Negative staining revealed the structure of the scales which consist of a baseplate with slightly thickened rim. The narrowing spine arises from the center of the baseplate. These results agree with previously studied isolates of P. vestita. The 18S rRNA gene sequence of the isolate had a very high similarity (99%) to P. vestita strain PV10. Phylogenetic analysis also showed that the isolate clustered with other Paraphysomonas sequences with high bootstrap support. Phylogenetic studies confirmed that P. vestita may be polyphyletic. No studies on the ultrastructure and phylogeny of a silica-scaled chrysophyte isolated in the Philippines have been reported so far. Results from this study may contribute to further ultrastructural and phylogenetic studies on aquatic flagellates and specifically to a revision of this potentially polyphyletic species.
Źródło:
Acta Protozoologica; 2010, 49, 2
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Small Free-Living Heterotrophic Flagellates from Marine Sediments of Gippsland Basin, South-Eastern Australia
Autorzy:
Lee, Won Je
Powiązania:
https://bibliotekanauki.pl/articles/763626.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Protist, heterotrophic flagellates, Ancyromonas impluvium, Kurnaimonas celeris, Sinistermonas sinistrorsus, Psammosa unguis, Gippsland Basin, cosmopolitan distribution.
Opis:
A total of 85 morpho-species of heterotrophic flagellates are reported from sediments at depths from 25–3000 m in the Gippsland Basin (Australia). They are drawn from the apusomonads, cercomonads, cryptomonads, euglenids, heteroloboseids, stramenopiles, thaumatomonads, and groups of uncertain taxonomic affinities (Protista incertae sedis). Three new species, Ancyromonas impluvium nov. spec., Kurnaimonas celeris nov. spec., Sinistermonas sinistrorsus nov. spec., one combination, Psammosa unguis nov. comb., and one unidentified species are described. The biogeography of the species seen in Gippsland Basin is discussed with reference to studies in other localities. It appears that many heterotrophic flagellates are cosmopolitan.
Źródło:
Acta Protozoologica; 2015, 54, 1
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Life Cycle, Morphology, Ontogenesis, and Phylogeny of Bromeliothrix metopoides nov. gen., nov. spec., a Peculiar Ciliate (Protista, Colpodea) from Tank Bromeliads (Bromeliaceae)
Autorzy:
Foissner, Wilhelm
Powiązania:
https://bibliotekanauki.pl/articles/763790.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Central America, division chain, life cycle, macrostome formation, merotelokinetal stomatogenesis, polytomic division, protist endemism, South America
Opis:
Bromeliothrix metopoides was discovered in tank bromeliads from Central and South America. Pure cultures could be established in various media stimulating growth of its food, i.e. bacteria and heterotrophic flagellates of the genus Polytomella. The new ciliate was investigated in the light- and scanning electron microscope, with various silver impregnation techniques, and with molecular methods, using the small-subunit rDNA. The morphology and its changes during the life cycle are documented by 167 figures and a detailed morphometry. Bromeliothrix metopoides is about 27–55 × 22–36 μm in size and has a complex life cycle with Metopus-shaped, bacteriophagous theronts and trophonts (microstomes) and obovate, flagellate-feeding macrostomes having a large, triangular oral apparatus. The thin-walled resting cysts of the theronts and trophonts are uniquely ellipsoidal, while the thick-walled cyst of the macrostome morph is globular. Reproduction occurs in freely motile condition either by binary fission or polytomy, producing a unique, motile “division chain” composed of four globular offspring, of which the central ones are connected by a curious, plug-like holdfast. Division is associated with a complete reorganization of the parental oral and somatic infraciliature. Stomatogenesis is merotelokinetal as in other members of the order Colpodida. The right polykinetid is generated by the rightmost postoral kinety, while the left polykinetid is produced by the two left postoral kineties and five left side kineties. The division in freely motile condition resembles the Exocolpodidae Foissner et al., 2002, to which Bromeliothrix is tentatively assigned, differing from Exocolpoda mainly by the formation of a macrostome morph and a division chain. Bromeliothrix has a ciliary and silverline pattern typical for members of the family Colpodidae. This matches the molecular classification which, however, hardly reflects the outstanding division and life cycle, suggesting some decoupling of morphological and molecular evolution. The specific morphological and ontogenetic traits of Bromeliothrix are interpreted as adaptations to the highly competitive habitat, favouring r-selected life strategies. Bromeliothrix metopoides is widespread in various tank bromeliads and can be easily cultivated in a wide variety of limnetic and terrestrial media. Thus, it remains obscure why this ciliate is restricted to tank bromeliads, i.e. did not occur in about 2,000 soil and freshwater samples investigated globally, including some 100 samples from Central and South America.
Źródło:
Acta Protozoologica; 2010, 49, 3
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Importance of tintinnids and Mesodinium rubrum in communities of planktonic ciliates in the shallow brackish lakes Gardno and Lebsko (northern Poland)
Znaczenie tintinnid i Mesodinium rubrum w zbiorowiskach planktonowych orzęsków w płytkich i słonawych jeziorach Gardno i Lebsko (północna Polska)
Autorzy:
Rychert, K.
Myszka, M.
Wielgat-Rychert, M.
Skuza, E.
Powiązania:
https://bibliotekanauki.pl/articles/84861.pdf
Data publikacji:
2017
Wydawca:
Akademia Pomorska w Słupsku
Tematy:
tintinnid
Mesodinium rubrum
protozoa
protist
Myrionecta rubra
Mesodinium major
distribution
salinity
eutrophic lake
planktonic ciliate
shallow lake
brackish lake
Lake Gardno
Lake Lebsko
Polska
Opis:
Ciliates constitute an important trophic link in aquatic environments, because they are essential food sources for zooplankton and fish. In this study, the spatial differences in abundance and composition of ciliate communities in relation to varying water salinity were investigated. The study was conducted in the large, brackish, eutrophic lakes Gardno and Łebsko. In the studied lakes, no significant differences among ciliate communities were identified among sampling sites. Ciliate communities in Lake Łebsko were characterized by a high contribution of tintinnids, with mean values at particular sites between 32% and 36%. In Lake Gardno, where salinity was lower, the importance of tintinnid ciliates increased after a marine water intrusion into the lake. In both lakes, the importance of tintinnids in ciliate communities was higher than in adjacent fresh and marine waters. Shortly after wind-driven intrusions of marine waters (backwaters), the marine and brackish mixotrophic ciliate Mesodinium rubrum was observed in both lakes. Once, in the eastern part of Lake Łebsko, Mesodinium major (= Mesodinium rubrum forma major) was observed after a strong backwater when salinity reached 5.4 PSU.
Orzęski stanowią istotne ogniwo troficzne w środowisku wodnym, ponieważ są ważnym źródłem pokarmu dla zooplanktonu i ryb. W prezentowanej pracy zbadano wpływ gradientu zasolenia na liczebność i skład zbiorowisk orzęsków. Badania prowadzono w dużych słonawych i eutroficznych jeziorach Gardno i Łebsko. Pomimo zróżnicowania przestrzennego zasolenia wody, nie wykazano istotnych różnic pomiędzy zbiorowiskami orzęsków obserwowanymi na poszczególnych stanowiskach. Zbiorowiska orzęsków w jeziorze Łebsko charakteryzowały się wysokim udziałem tintinnid, które wnosiły średnio na poszczególnych stacjach od 32% do 36% liczebności. W jeziorze Gardno, w którym zasolenie było niższe, znaczenie tintinnid wzrosło po intruzji wód morskich do jeziora. W obu badanych jeziorach znaczenie tintinnid w zbiorowiskach orzęsków było wyższe niż w przyległych wodach słodkich i morskich. Krótko po spowodowanych wiatrem intruzjach wody morskiej (cofkach) w obu jeziorach był obserwowany słono- i słonawowodny miksotroficzny orzęsek Mesodinium rubrum. Po silnej cofce, kiedy zasolenie we wschodniej części jeziora Łebsko sięgnęło 5,4 PSU, zaobserwowano tam Mesodinium major (= Mesodinium rubrum forma major).
Źródło:
Baltic Coastal Zone. Journal of Ecology and Protection of the Coastline; 2017, 21
1643-0115
Pojawia się w:
Baltic Coastal Zone. Journal of Ecology and Protection of the Coastline
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-12 z 12

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