Species Of Heterotrophic Flagellates Research Articles

HETEROTROPHIC FLAGELLATES OF THE UZH RIVER, THEIR SEASONAL DYNAMICS, TAXONOMIC AND TROPHIC STRUCTURES

The article presents the results of the study of taxonomic and trophic structure, as well as features of seasonal dynamics of heterotrophic flagellates of the Uzh River (Korosten). In the investigated reservoir, 21 species of heterotrophic flagellates were identified, among which 7 species belong to the Excavata supergroup, 9 to the SAR (systematic group including Stramenopiles, Alveolata and Rhizaria) and 5 species of uncertain systematic position. According to the nutrition strategy, 76% of the species found are actively searching for food and 24% are catching or intercepting a food particle with flagella, absorbing it directly on the cell surface; the main trophic group are bacteriodetritophages-collectors, they amount 62%, at 14% are bacteriodetritophages-filterers and euryphages; and 10% (2 species) are predators – Allantion tachyploon and Phyllomitus apiculatus. Peaks of heterotrophic flagellates were recorded in June – 9 species and in October – 7 species, at the highest number in June – 5410 copies/ml and in April – 5062 copies/ml. The lowest species wealth was observed in January – 2 species, at the lowest number in January – 116 copies/ml and in December – 174 copies/ml. It has been established that eudominant species were absent in June and August due to the dominance of other flagellates. Most often, in January, February, May, July and December, this was Bodo designis. Goniomonas truncata and Spumella vivipara are slightly inferior. A. saltans, Rhynchomonas nasuta and Paraphysomonas vestita were eudominants in only one month. Almost the same trend persists among dominant species, most often B. designis and G. truncate. The predominant subdominants are represented by S. major, Heteromita minima and Protaspis gemmifera, moreover S. major, P. geminifera, P. apiculatus, A. tachyploon, Anthophysa vegetans and Protaspis simplex occur only in this flagellate group.

First Data on Heterotrophic Flagellates and Heliozoans of Ethiopia

The species composition and external morphology of heterotrophic flagellates and heliozoans were studied in the freshwater habitats of various types in Ethiopia: Lake Tana and the rivers discharging into Lake Tana; two lakes in the Rift Valley; puddles on the banks of rivers and lakes and in a rice field. Altogether, 21 species and 11 forms of flagellates and two species of heliozoans from five macrotaxonomic clusters have been recorded. Many species of heterotrophic flagellates are also known from marine and soil habitats. Most flagellates were bacterivorous, and only two species were carnivorous. Original line drawings, photographs, and descriptions of the species, with an emphasis on the cell structural features, are provided. All identified species are new to the fauna of Ethiopia.

First Reports on Heterotrophic Flagellates in the Mires of Arkhangelsk Region, Russia

The species composition and morphology of heterotrophic flagellates collected from mire hollows, flowing waterlogged mire sites, mire pools, streams, and watercourses were studied in Pinega district, Arkhangelsk region, Russia. Fifty species of flagellates belonging to four macrotaxonomic clusters were recorded. Most of the flagellates were bacterivorous; two species were predators, and two species were omnivorous. Each type of mires and mire waterbodies has a particular set of species (ANOVA: F = 15.5, p< 0.001). Thirty-four species of heterotrophic flagellates were found in eutrophic mires (interhummock spaces and streams), and 26 species inhabited oligotrophic mires (mire hollows, streams, and pools). The protist fauna was extremely poor in mire pools (two species). Nonparametric MDS-analysis revealed four groups of communities: (1) mire hollows and waterlogged mire sites; (2) interhummock spaces, mire hollows, and streams; (3) degrading hollows-rimpi; (4) mire pools. The species richness depended on electric conductivity of the water (τ = 0.65, p = 0.002). Descriptions, drawings and pictures showing the details of cell structures are given for the most poorly studied species. All the species recorded are new for the fauna of Arkhangelsk region.

Biodiversidad de protistas (flagelados heterótrofos) en México

In Mexico, 146 species of heterotrophic flagellates, included in Rhizaria, Stramenopiles and Excavata, have been reported. Parabasalids, opalines, trypanosomatids and bodonids have the higher specific richness. The genera Trypanosoma, Trichomonas, Metadevescovina and Bodo, contain the greatest number of species, and Bodo has been reported from a variety of habitats. Trypanosoma is the genus with the widest geographic distribution due to its presence in 20 Mexican states. We conclude that the study of heterotrophic flagellates is only partial and new species, new habitats and new geographic records are possible.

Heterotrophic flagellates from freshwater and soil habitats in subtropical China (Wuhan Area, Hubei Province)

We studied the diversity of heterotrophic flagellates from the sandy sediments of the Yangtze River, sandy and silty sediments of Donghu Lake, soil, moss and litter from the Luojiashan and Moshan hills as well as litter from the floodplain near Donghu Lake in April 2010. Sixty-seven heterotrophic flagellate species were identified by means of phase and interference contrast light microscopy and transmission electron microscopy. The majority of the observed flagellates were bacterivorous. Local species richness of river sediment communities was significantly lower than that of lake sediments and terrestrial habitats. The communities from the terrestrial habitats were more heterogeneous than those from freshwater sediments. Common species for the aquatic habitats were Rhynchomonas nasuta, Paraphysomonas sp., Neobodo designis, N. curvifilis, Bodo saltans and Spumella spp. In the soils only Spumella spp. was found in the majority of samples. Most characteristic taxa for the lake sediments were Helkesimastix faecicola, Petalomonas minuta, P. pusilla, Diphylleia rotans, Amastigomonas caudata. Amoeboflagellates such as Cercomonas angustus, C. granulifera, Paracercomonas crassicauda were specific for the terrestrial habitats. There were no specific taxa in the river sediments. The majority of the heterotrophic flagellates identified in this survey have been noted in China earlier. They are common (and usually predominant) for other regions in both freshwater and soil habitats.

Ecological Spectrums of Heterotrophic Flagellates (Protista) in Water Bodies of Ukrainian Polissya Area

Ecological Spectrums of Heterotrophic Flagellates (Protista) in Water Bodies of Ukrainian Polissya Area Dependence of 26 heterotrophic flagellate species development in central part of Ukrainian Polissya area from operating pH and concentrations of dissolved organic matter and oxygen in the waters is considered. Narrowing of existence spectrums in certain types of water body characteristic for some species of heterotrophic flagellates is stated; this peculiarity is strongly expressed in the bogs where specific complex of hydrochemical conditions to have a place.

Heterotrophic flagellates in the littoral and sublittoral zones of the southeast part of the Pechora Sea

For the first time, data on the heterotrophic flagellate fauna in the littoral and the sublittoral zones of the southeastern part of the Pechora Sea were obtained. Sixty-six heterotrophic flagellate species were found in the study region: 48 and 42 species were found on the shelf and in the intertidal zone, respectively. The most common species were Cafeteria roenbergensis, Paraphysomonas sp., Ancyromonas sigmoides, Cafeteria minuta, Actinomonas mirabilis, and Spumella sp. The littoral fauna of the heterotrophic flagellates was more peculiar than the sublittoral fauna and equally rich. In the region studied, the community can be divided into two types: (a) the predominantly littoral community characterized by a special composition of the dominant species and by high similarity between its local varieties and (b) the heterogeneous predominantly sublittoral community characterized by a lack of a complex of particular species. The local diversity of the heterotrophic flagellate community was low (on the average, 4.5 species per one sample 1 cm3 in volume). The overall distribution pattern of the flagellates was extremely heterogeneous. The large amount of species that were encountered only once causes a great variability in the species structure from one station to another. The total number of the species monotonously increased with the growth in the number of samples and no manifested saturation of the cumulative curve was reached. This indicates the potentially greater diversity of the heterotrophic flagellate species in the region studied.

Digestion of bacterial macromolecules by a mixotrophic flagellate, Ochromonas sp., compared with that by two heterotrophic flagellates, Spumella pudica and Bodo saltans

Digestion of bacterial biomass by three species of phagotrophic flagellates was studied using radioactive tracer techniques and short-term feeding experiments. Macromolecules of two different bacterial strains and natural limnic bacterioplankton were pulse-chase-labelled with one of the following precursors 3H-thymidine, 35S-/14C-methionine or 14C-leucine, before bacteria were fed to flagellates and radioactive labels were traced into flagellate macromolecules. The concentrations of prey and predators were monitored by flow cytometry. The aim of the work was to compare efficiencies of bacterial macromolecule accumulation by mixotrophic (Ochromonas) and heterotrophic (Spumella and Bodo) flagellates. We observed that flagellate accumulation efficiency of bacterial macromolecules labelled with thymidine (mean 15–30%, depending on flagellate species) was lower than of bacterial macromolecules labelled with amino acids (mean 26–68%). Heterotrophic flagellate species had similar accumulation efficiencies of bacterial molecules, when either leucine (26–42%) or methionine (31–41%) was used as a tracer. In contrast the mixotrophic flagellate accumulated significantly more residues of labelled methionine (68%) than of labelled leucine (54%). Methionine seems to be accumulated as an intact molecule and possibly Ochromonas preferentially accumulated methionine as an additional source of reduced sulphur. Protozoan accumulation efficiencies did not differ significantly whether the pulse-labelled bacterial prey were from growing or long-term starvation cultures. Our results suggest that labelled amino acids are more appropriate than labelled thymidine for studying transfer of bacterial biomass within food webs.

Benthic-pelagic coupling: a comparison of the community structure of benthic and planktonic heterotrophic protists in shallow inlets of the southern Baltic

1. The taxonomic composition, abundance and biomass of heterotrophic protists (ciliates, heterotrophic flagellates (HF), rhizopods and actinopods) in the sediment and water column of shallow inlets of the Southern Baltic was studied under a variety of environmental conditions during 1996–1997. A shallow, highly eutrophic station and a deeper, less eutrophic station were compared. 2. Community biomass ranged from 0.12 to 0.34 μg C cm−3 in the water column and from 1.5 to 105 μg C cm−3 in the sediment. Heterotrophic protists dominated zooplankton biomass at both stations (73% and 84% mean contribution), while they were of minor importance within the zoobenthos. Expressed per unit area, benthic biomass contributed a significant part (44% and 49%) to the total heterotrophic protistan community at both stations. 3. Although the methodology for counting ciliates and HF was focussed on a high taxonomic resolution, the results reveal some general trends in the distribution of heterotrophic protists: protozooplankton biomass was dominated by flagellates (80% mean biomass contribution) at the shallow station and by ciliates (73% mean biomass contribution) at the deep station. In the benthos at both stations, ciliates were the dominant protozoans, followed by the hitherto little-studied rhizopods (25% and 35% mean biomass contribution) and flagellates. 4. The degree of benthic–pelagic coupling differed between taxonomic groups. Benthic and pelagic communities of ciliates showed little taxonomic overlap. In contrast, many heterotrophic flagellate species were found both in the benthos and in the pelagic. These benthic–pelagic species contributed significantly to the biomass of HF in the water column. The planktonic rhizopod community consisted of a subset of those species found in the benthos. 5. The abundance of benthic and pelagic protists was positively correlated at the shallow station, but taxonomic data indicate that the direct exchange between benthic and pelagic communities was only partly responsible.

Diversity and Geographic Distribution of Free-Living Heterotrophic Flagellates – Analysis by PRIMER

Data on the distribution of approximately 350 species of heterotrophic flagellates (protozoa) in 31 communities from sites around the world - inclusive of marine and freshwater habitats, water column and benthic habitats, and 'extreme' (i.e. anoxic and hypersaline) habitats - are analysed by the Cluster algorithm in the PRIMER package. We have sought to minimise the impact of factors extrinsic to the actual distribution of organisms which may distort our perception of the geographic patchiness of organisms. In our analyses, communities from areas which are geographically close to each other do not cluster together. Communities from similar habitats cluster together (i.e., water column communities group together, as do benthic communities, or freshwater and marine communities), and communities from more unusual habitats segregate from those of less 'extreme' habitats. We argue that our capacity to draw robust conclusions on the distribution of these organisms is hampered by under-reporting. We favour a model in which there are relatively few species of free-living heterotrophic flagellates, and that most of these species have a cosmopolitan distribution.