Protozoan Fauna Research Articles

Vertical variations and environmental heterogeneity drove the symphony of periphytic protozoan fauna in marine ecosystems

Periphytic protozoa are esteemed icons of microbial fauna, renowned for their sensitivity and role as robust bioindicators, pivotal for assessing ecosystem stress and anthropogenic impacts on water quality. Despite their significance, research exploring the community dynamics of protozoan fauna across diverse water columns and depths in shallow waters has been notably lacking. This is the first study that examines the symphony of protozoan fauna in different water columns at varying depths (1, 2, 3.5 and 5 m), in South China Sea. Our findings reveal that vertical changes and environmental heterogeneity plays pivotal role in shaping the protozoan community structure, with distinct preferences observed in spirotrichea and phyllopharyngea classes at specific depths. Briefly, diversity metrics (i.e., both alpha and beta) showed significantly steady patterns at 2 m and 3.5 m depths as well as high homogeneity in most of the indices was observed. Co-associations between environmental parameters and protozoan communities demonstrated temperature, dissolved oxygen, salinity, and pH, are significant drivers discriminating species richness and evenness across all water columns. Noteworthy variations of the other environmental parameters such as SiO3–Si, PO4−-P, and NO2––N at 1 m and NO3−–N, and NH4+–N, at greater depths, signal the crucial role of nutrient dynamics in shaping the protozoan communities. Moreover, highly sensitive species like Anteholosticha pulchara, Apokeronopsis crassa, and Aspidisca steini in varying environmental conditions among vertical columns may serve as eco- indicators of water quality. Collectively, this study contributes a thorough comprehension of the fine-scale structure and dynamics of protozoan fauna within marine ecosystems, providing insightful perspectives for ecological and water quality assessment in ever-changing marine environments.

The record of Vannella species (Vannellidae, Discosea, Amoebozoa) from freshwater sources in Dakahlyia Governorate, Egypt

The River Nile is the main source of fresh water in Egypt, where its water is used for irrigation, drinking, fisheries, industrial uses, and recreation. For sustainable utilization of the River Nile and its branches in the Nile Delta region, it is necessary to monitor regular investigation for the biodiversity of protozoan fauna in the Damietta branch and other freshwater canals in Dakahlyia Governorate. Water samples were collected monthly from different water sources, for 1 year, and examined for protozoans, using phase-contrast microscopy and recorded video films, The genus Vannella Bovee 1965 is recorded for the first time in four freshwater localities: Demietta branch of the River Nile, Mansouria Canal, Bouhia Canal, and Bahr El-Saghir Canal. A detailed morphological description with a brief report of their locomotion has been given for four morphologically different Vannella species. The locomotive form of Vannella sp.1 has a long pointed posterior tail and 2 lateral posterior processes. Such a tail was absent in other Vannella species. Vannella sp.2 is unique among other recorded species, where its locomotive form possesses a long posterior rounded tail region and a frontal hyaloplasm provided with a wavy surface that forms several lobes and finger-like processes during locomotion. In addition, the hyaloplasm produces several transverse waves that vary in thickness and density. The floating form of Vannella sp.2 is of a radial type and has comparatively long hyaline pointed and spiral pseudopodia. The process of transformation of locomotive form to floating form in Vannella sp.2 has been followed up using several recorded video films. The locomotive form of Vannella sp.3 is bear-shaped, while that of Vannella sp.4 has variable shapes from semicircular to rectangular and sometimes fan-shaped. During movement in vivo, locomotive cells of all Vannella species, except Vannella sp.1, move in nearly a straight line, but there were variations in their rate of locomotion. Vannella sp.4 recorded the highest rate (6.8 µm/s), followed by Vannella sp.2 (4.5 µm/s), Vannella sp.3 (2.4 µm/s), and finally Vannella sp.1 (1.0 µm/s). Molecular studies and transmission electron microscope examinations are still needed to confirm the precise identity of each Vannella species.

Microplastics drive community dynamics of periphytic protozoan fauna in marine environments.

The pollution of microplastics (MPs) to the marine environment has become a widespread focus of attention. To assess MP-induced ecotoxicity on marine ecosystems, periphytic protozoan communities were used as test organisms and exposed to five concentrations of MPs: 0, 1, 5, 25, and 125mgl-1. Protozoan samples were collected using microscope slides from coastal waters of the Yellow Sea, northern China. A total of 13 protozoan species were identified and represented different tolerance to MP-induced ecotoxicity. Inhibition effects of MPs on the test protozoan communities were clearly shown in terms of both the species richness and individual abundance and followed linear relationships to MP concentrations. The community patterns were driven by MPs and significantly shifted at concentrations over 5mgl-1. Our findings demonstrated that MPs may induce the community-level ecotoxic response of periphytic protozoan fauna and followed significant community dynamics. Thus, it is suggested that periphytic protozoan fauna may be used as useful community-based test model organisms for evaluating MP-induced ecotoxicity in marine environments.

A community-based bioassay for the salinity stress on periphytic protozoan fauna in marine ecosystems

To evaluate the salinity stress on ecological quality using protozoa, a 1-month baseline study was conducted along a gradient of salinity 9, 19, 29, 39, and 49 PSU (practical salinity unit). Protozoan samples were collected from an intertidal zone of the Yellow Sea, northern China. The findings demonstrated that (1) protozoan species represented different tolerance to scales of salinity stress; (2) the species richness decreased with increase of salinity, while in individual abundances sharply dropped with both increase and decrease of salinity compared to the control (29 PSU); (3) the probit regression revealed the median inhibition concentrations (IC50) values 21.14 and 38.24 PSU for low (<29 PSU) and high (>29 PSU) situations, respectively; and (4) high salinity stress significantly shifted the community pattern of the protozoan fauna. Therefore, it is suggested that periphytic protozoan communities may be used a useful bioindicator of ecological quality under salinity stress in marine ecosystems.

Effects of continuous warming on homogeneity of periphytic protozoan fauna in marine ecosystems

As a powerful biological indicator, multivariate dispersion in a community is widely used to evaluate the biological evaluation of environmental heterogeneity. To investigate the effects of persistent warming on microbial fauna in marine environments, the periphytic protozoan communities were used as test organisms and incubated in five temperature-controlled circulation system at 22 (control), 25, 28, 31 and 34 °C, respectively. The results showed that (1) there was a clear variation in species occurrence, and the α-/γ-diversity measures decreased with the increase of temperatures; (2) the compositional pattern was significantly driven by the persistent warming compared to community pattern from species-abundance data; and (3) both traditional β-diversity and multivariate dispersion measures on species compositional matrix were significantly correlative with changes in the temperature. Therefore, it is suggested that continuous temperature fluctuations have a greater impact on homogeneity of species composition of protozoan communities than that of their community structure.

Continuous warming shifts the community pattern of periphytic protozoan fauna in marine environments

Protozoan fauna is playing an important role in the functioning of microbial food webs by transferring the flux of material and energy from low to high tropic levels in marine ecosystems. To assess effects of elevated temperature on the marine ecosystem, periphytic protozoan communities were used as the test microbial fauna, and were incubated in a temperature-controlled circulation system in a successive temperature gradient of 22 (control), 25, 28, 31 and 34 °C. The results showed that: (1) the test microbial fauna was shifted in both species composition and community structure; (2) the average taxonomic distinctness represented a clear decreasing trend, (3) while the variation in taxonomic distinctness significantly increased with increase of water temperature; and (4) the community pattern was significantly departed from an expectation when temperature increased by 12 °C. These results suggested that Protozoa may be used as a useful bioindicator of global warming in marine ecosystems.

Gregarine Stylocephalus oblongatus (Apicomplexa, Eugregarinida, Gregarinidae) from the Intestine of Opatrum sabulosum (Coleoptera, Tenebrionidae) in the Reclamation Areas of Pokrovsky Mining and Processing Plant: the First Report and Morphometric Variabil

The peculiarities of variability of forms and sizes of the gregarine Stylocephalus oblongatus (Hammerschmidt, 1838) Watson, 1916 in the intestines of the Opatrum sabulosum (Linnaeus, 1761) from the sites of reclamation of lands disturbed by mining industry in the south of the area of the Steppe Dnipro were investigated. This is a new record for the protozoan fauna of Ukraine. The prevalence of host infection was 7.44 %. To determine the limits of variability, a sample of 71 specimens was used. Gamonts of S. oblongatus were analysed by 15 linear characteristics and 18 indices of the ratio of these characteristics. For linear parameters, the average coefficient of variation was 33 %. The minimum values of the coefficient of variation were characteristic for the lengths of the gamont, protomerite and their ratio. The principal component analysis identified 4 principal components, the value of which was greater than 1. Together they explained 73 % of the variability. Cluster analysis identified 4 clusters that can be explained as 2 morphotypes and 2 morphosubtypes. The greatest contribution to the overall variability of S. oblongatus gamonts is made by the position of the cell nucleus of the gamont in relation to the septum, the width of the septum and protomerite and the distance from the posterior end of the deuteromerite to the axis of its maximum width. The observed morphological differences can be explained by different degrees of host infection. It is important to compare the obtained information on intraspecific variability of S. oblongatus with similar data from natural ecosystems, as well as from agrocenoses and urban populations of O. sabulosum.

Can salinity variability drive the colonization dynamics of periphytic protozoan fauna in marine environments?

To investigate effects of salinity variability on colonization dynamics of periphytic protozoan fauna, a 21-day study was conducted in temperature-controlled circulation systems (TCCSs). Periphytic protozoan communities were incubated using glass slides as artificial substrata in five TCCS aquaria with a large-scale salinity gradient of 9, 19, 29 (control), 39, and 49 PSU, respectively. The colonization dynamics were observed on days 3, 5, 7, 10, 14, and 21. The colonization dynamics were well fitted to the MacArthur–Wilson and logistic model equations in colonization and growth curves in all five treatments, respectively. However, the maximum species richness and abundance were reduced, and the colonization patterns were significantly shifted in four treatments with salinity changed by 20 PSU compared to the control (29 PSU). Thus, it is suggested that the large-scale salinity variability may reduce the species richness significantly and affect colonization dynamics of periphytic protozoan fauna in marine environments.

Can tidal events shape the taxonomic breadth of periphytic protozoa in intertidal zone ecosystems?

To evaluate the influence of tidal events (tidal disruption) on the taxonomic breadth of periphytons in intertidal zone ecosystems, a 1-month baseline survey on protozoan periphyton fauna was studied at five sampling sites from the highest tideline to the lowest (sites A–E) in an intertidal zone of the Yellow Sea, northern China. Samples were collected using an artificial substratum (glass slides) in the sea water with the sediment taken at each sampling site after a 14-day exposure period. The protozoan fauna showed a significant variation in both taxonomic composition and taxonomic distinctness measures along five tidelines. Based on the pair-wised taxonomic distinctness measures (Δ+ and Λ+), the expectation test revealed an increasing departure of the periphyton samples from an expected taxonomic breadth from the highest to the lowest tideline. Therefore, it suggests that tidal events (tidal disruption) may significantly shape the taxonomic breadth of protozoan periphyton fauna in intertidal zones of marine ecosystems.

Antibiotic nitrofurazone drives the functional dynamics of periphytic protozoan fauna in marine environments

The use of functional traits of a community as a method to measure its functional dynamics in response to environmental change has gained attention because trait-based approaches offer systematic opportunities to understand the interactions between species diversity and ecosystem function. However, the relationship between functional traits of periphytic protozoa and contamination of aquatic habitats with antibiotics is poorly understood. In this study, we investigated the influence of the antibiotic nitrofurazone on functional traits of marine periphytic protozoan fauna. For this purpose, the protozoan assemblages were collected from coastal waters of the Yellow Sea at Qingdao, northern China, during four seasons of a one-year cycle using glass microscope slides as artificial substrates. The test protozoan communities were then exposed to various treatments of nitrofurazone in laboratory bioassay experiments. Our results demonstrated that the modalities of the functional traits of protozoan communities were generally driven by nitrofurazone toxicity. Briefly, R-mode linked to Q-mode (RLQ) and fourth-corner analyses revealed strong positive correlations between functional traits and nitrofurazone treatments. Trait syndromes in terms of body length, width, weight, height, and size to volume ratios were significantly influenced by nitrofurazone exposure. In particular, small and medium body size species of different feeding types, i.e., algivores, bacterivores, raptors or non-selectives, were more sensitive than other protozoan species to higher concentrations of nitrofurazone. Our findings demonstrate that antibiotic toxicity is likely to affect periphytic protozoan community function, shape the functional processes, and induce toxic responses in the community. The findings of this study suggest that periphytic protozoan communities and their functional traits are suitable bioindicators for evaluating the ecotoxicity of nitrofurazone in marine environments.

Insights for monitoring surveys into influence of tidal events on protozoan periphyton fauna along the tidelines of Yellow Sea, Northern China

To explore the influence of tidal events on protozoan periphyton fauna along tidelines, a 1-month baseline survey for bioassessment was conducted in an intertidal zone of the Yellow Sea, Northern China. A total of 27 protozoans species were identified among five sampling sites along five tidelines (sites A–E). The periphytic protozoans showed a significant variation in species distribution and community pattern along five tidelines. Species richness decreased from the high tideline (site A) and reached the minimum value at the middle tideline (site C), followed by an increase up to the low tideline (site E). Individual abundances peaked at site C and leveled off at the other four tidelines. Species richness, evenness, and diversity showed low value at site C compared with those at the other four sites. These findings suggest that periphytic protozoan fauna was shaped by tidal events along the tidelines of marine ecosystems.

Insights into seasonal shift in the homogeneity of periphytic protozoan fauna in coastal waters of the Yellow Sea, northern China

The seasonal shift in the homogeneity of the periphytic protozoan fauna was studied based on a four-season baseline survey in the coastal waters of the Yellow Sea, northern China. Samples were collected using glass microscope slides as an artificial substratum at a depth of 2 m after the immersion time of 14 days during each of the four seasons (winter, spring, summer, and autumn, 2017). The protozoan fauna showed a clear seasonal shift in species composition and a significant variation in homogeneity in terms of both compositional and community structure during four seasons. The dispersion measures and β-diversity index represented an increase in the trend from spring to winter. These findings suggest that the homogeneity of the periphytic protozoan fauna was subject to a significant variability shaped mainly by species composition during a four-season cycle in marine ecosystems.

Studies on the free-living protozoan fauna of estuaries in the coastal zone of Tamil Nadu, India

A study was conducted to explore and document the free living protozoan diversity in estuaries in coastal zone of Tamil Nadu for the first time. The study covered the estuaries, viz., Arasalar, Vettar, Kaduviyar, Kollidam, Vellar, Marakkanam, Pulicat and Kaliveli of coastal zone of Tamil Nadu and resulted in the occurrence of 58 species of free-living protozoa including testate amoebae, tintinnids and foraminiferans from different estuaries coming under 9 genera and 6 families. All the species are new records from these estuaries and 5 species constituted as new records to India, viz., Arcella excavata Cunningham 1919, Centropyxis delicatula Penard 1902, Centropyxis discoides Penard 1902, Difflugia binucleata Penard 1902 and Difflugia geosphaira Ogden 1991.

Insights into β-diversity of periphytic protozoan fauna along the water column of marine ecosystems

It has been increasingly recognized that there is high relevance in determining the β-diversity of communities along an environmental gradient for bioassessment of environmental quality status. To evaluate the vertical variations in β-diversity of periphytic protozoan fauna, in response to environmental heterogeneity in marine ecosystems, a baseline survey was conducted at the four water depths in the coastal waters of the Yellow Sea, northern China. Results demonstrated that (1) the species distribution presented different patterns at four water depths; (2) both compositional and community structure showed a significant vertical variation in multivariate dispersions from surface layer to the deeper layers; and (3) β-diversity measures generally increased from depths of 1 m to 5 m. These findings suggest that the homogeneity in the periphytic communities are of a high variability along the water column of marine ecosystems.

Ciliated Protozoan Fauna in the Forestomach of Dromedary Camels (Camelus dromedarius) in Libya.

Species composition and distribution of ciliated protozoa obtained from the forestomach of 20 dromedary camels living in Zawiya, Libya were examined. Nineteen species and 10 morphotypes belonging to eight genera were identified. The mean number of ciliates was 54.2 ± 32.9 × 104 cells ml-1 in the forestomach contents, and the mean number of ciliate species per host was 6.5 ± 2.9. Entodinium and Epidinium were the main genera, as these ciliates were found consistently at higher proportions than those of the other genera. In contrast, Ophryoscolex and Polyplastron were only observed at low frequencies. Diplodinium rangiferi, Entodinium ellipsoideum, E. simulans, and Polyplastron multivesiculatum were new endosymbionts recorded from camels.

Biodiversity of Tintinnids (Tintinnida) in Khanh Hoa - Binh Thuan waters

Tintinnidsarean important protozoan group in the aquatic food web and had been widely studied in various waters. There are about 1000 known species in the world. However, there have beenvery few taxonomic studies in Vietnam and therefore the number of Tintinnid taxa and their distribution are poorly known. Thepresent study documents 65 tintinnids species belonging to 30 genera and 13 families in samples collected from Khanh Hoa - Binh Thuan waters in 2016 and 2017. There were 17 new taxa records for Vietnam protozoan fauna, raising the number of tintinnids recorded in Vietnam to 125 taxa. Tintinnid assemblages in Khanh Hoa-Binh Thuan waters shared about 17 species with Ha Long Bay, 32 species with Con Co island and 26 species with coastal waters of South Vietnam. Analysis of species diversity shows that the Shannon diversity index H' varied from 1.5 to 2.6. Distribution of species numbers and diversity in the Khanh Hoa - Binh Thuan waters revealed possible combined effects of hydrographical activities (e.g. upwelling), Mekong river influent (e.g. salinity), and food available on tintinnid communities. Citation: Nguyen Thi Kieu, Phan Tan Luom, Nguyen Tam Vinh, Nguyen Ngoc Lam, Josepth P. Montoya, Doan Nhu Hai, 2017. Biodiversity of Tintinnids (Tintinnida) in Khanh Hoa - Binh Thuan waters. Tap chi Sinh hoc, 39(4): 421-433. DOI: 10.15625/0866-7160/v39n4.11033. *Corresponding author:haidoan-ion@planktonviet.org.vn Received 19 September 2017, accepted 12 December 2017

First record of protozoan parasites in cyprinid fish, Schizothorax niger Heckel, 1838 from Dal lake in Kashmir Himalayas with study on their pathogenesis

Trichodina heterodentata Duncan, 1977 and Ichthyophthirius multifiliis Fouquet, 1876 obtained from gills during a parasitological survey conducted for the protozoan parasitic fauna of Schizothorax niger a snow trout in Dal Lake, Kashmir, India during the period October 2013 and March 2015. Thirty out of 180 fish were found infected with protozoan parasites. During the study of their pathogenecity the most common deteriorating signs observed in gill tissue were necrosis, hypertrophy, hyperplasia and fusion of secondary lamellae. Prevalence of infection was found to be 16.66%. This is the first record of the protozoan fauna of the schizothoracines from Kashmir valley, India.

A Coprological Survey of Protozoan and Nematode Parasites of Free-Ranging Chacma Baboons (Papio ursinus) in the Southwestern Cape, South Africa

This study provides data on gastrointestinal parasite infections in the geographically isolated and locally fragmented Cape Peninsula baboon population and two troops from neighbouring populations in the Western Cape Province, South Africa. We obtained data on parasite diversity and prevalence from 616 faecal samples collected from over 350 individuals in eight troops between July 2006 and May 2008. We processed faecal samples using a modified formalin-ether sedimentation technique and identified nematode eggs and protozoan cysts. We recovered seven nematode genera (Trichuris sp., Oesophagostomum sp., Trichostrongylus sp., Physaloptera sp., Ascaris sp., an unidentified hookworm morphotype, and an unidentified spirurid) and eight protozoan species (Balantidium coli, Entamoeba coli, E. histolytica/dispar, E. chattoni, E. hartmanni, lodamoeba bütschlii, Endolimax nana and Chilomastix mesnili). The nematode and protozoan fauna of the Cape Peninsula baboon population was similar to both neighbouring and geographically distinct chacma baboon populations in South Africa. Parasite prevalence was variable across study sites and seasonality did not appear to have an effect on patterns of infection. The finding of the eggs of an ascarid, possibly Ascaris sp., in the Cape Peninsula baboon population represents the first report of this nematode genus in wild baboons in South Africa.

Protozoan Fauna and Abundance in Aeration Tanks of Three Municipal Wastewater Treatment Plants in the Eastern Cape Province of South Africa

Protozoan Fauna and Abundance in Aeration Tanks of Three Municipal Wastewater Treatment Plants in the Eastern Cape Province of South Africa

Symbiotic “Archaezoa” of the Primitive TermiteMastotermes darwiniensisStill Play a Role in Cellulase Production

The relictual Mastotermes darwiniensis is one of the world's most destructive termites. Like all phylogenetically basal termites, it possesses protozoa in its hindgut, which are believed to help it digest wood. L. Li, J. Frohlich, P. Pfeiffer, and H. Konig (Eukaryot. Cell 2:1091-1098, 2003) recently cloned the genes encoding cellulases from the protozoa of M. darwiniensis; however, they claimed that these genes are essentially inactive, not contributing significantly to cellulose digestion. Instead, they suggested that the protozoa sequester enzymes produced by the termite in its salivary glands and use these to degrade cellulose in the hindgut. We tested this idea by performing gel filtration of enzymes in extracts of the hindgut, as well as in a combination of the salivary glands, foregut, and midgut. Three major cellulases were found in the hindgut, each of which had a larger molecular size than termite-derived salivary gland enzymes. N-terminal amino acid sequencing of one of the hindgut-derived enzymes showed that it was identical to the putative amino acid sequence of one mRNA sequence isolated by Li et al. (Eukaryot. Cell 2:1091-1098, 2003). The overall activity of the hindgut cellulases was found to be of approximately equal magnitude to the termite-derived cellulases detected in the mixture of salivary gland, foregut, and midguts. Based on these results, we conclude that, contrary to Li et al. (Eukaryot. Cell 2:1091-1098, 2003), the hindgut protozoan fauna of M. darwiniensis actively produce cellulases, which play an important role in cellulose digestion of the host termite.