Freshwater Testate Amoebae Research Articles

Freshwater Testate Amoebae (Arcellinida) Response to Eutrophication as Revealed by Test Size and Shape Indices

We review the potential for applying traits-based approaches to freshwater testate amoeba, a diverse protist group that are abundant in lakes and are valuable ecological indicators. We investigated the efficacy of geometric morphometric analysis to define Arcellinida test size and shape indices that could summarize freshwater testate amoeba community dynamics along a temporal gradient of eutrophication in Loch Leven, Scotland (United Kingdom). A cluster analysis of test size and shape indices yielded three clusters, each dominated by a single shape: elongate, spherical and ovoid. When plotted stratigraphically, we observed increases in spherical tests, decreases in elongate tests and shrinking of test size coeval with eutrophication in Loch Leven. Decreases in the elongate cluster may reflect benthic conditions with reduced oxygen levels, while increases in the spherical cluster are likely associated with an expanding macrophyte community that promoted pelagic and epibiotic life habits. Shrinking of test size may be a stress response to eutrophication and/or warming temperatures. Tracking community dynamics using test size and shape indices was found to be as effective as using species-based approaches to summarize key palaeolimnological changes, with the added benefits of being free from taxonomic bias and error. The approach thus shows significant potential for future studies of aquatic community change in nutrient impacted lakes.

Freshwater testate amoebae from waterbodies of North Vietnam with the finding of indicator species

Testate amoebae are an irreplaceable key component of microbial communities in many aquatic and soil ecosystems and well known as useful bioindicators. In the present work, testate amoebae compositions in different-type biotopes of freshwater waterbodies of North Vietnam were investigated for the first time. A total of 80 species and subspecies belonging to 12 genera and 8 families were identified from 105 samples collected in Suoi Hai, Xuan Khanh, Cam Quy, Ho Ba reservoirs, and Van Long wetland. Difflugia acutissima, D. brychtai, D. distenda, D. elegans teres, D. glans, and Awerintzewia cyclostoma were new records for Vietnam. Centropyxis aculeata, D. schurmanni, and D. elegans were the most common species in all types of biotopes including plankton, benthos, and periphyton. The results of two-way ANOVA showed statistically significant interaction effects of waterbodies and the type of biotopes on testate amoebae species richness per sample (p < 0.05). The simple effects analysis was performed to compare species richness per sample within studied waterbodies concerning the type of biotope and vice versa. A statistically significant difference (p < 0.001) in testacean mean species richness per sample was observed between aquatic macrophytes in periphytonic biotope. The results of NMDS and ANOSIM analyses showed statistically significant difference in the testate amoeba communities between studied waterbodies (ANOSIM r = 0.16, p < 0.001) and biotopes (ANOSIM r = 0.29, p < 0.001). The indicator value of species (p < 0.05) selected 17 indicator species including one for plankton, one for benthos, and 15 for periphyton. These findings provide new useful information for further paleoenvironmental researches using testate amoebae as bioindicators.

A comparative analysis of freshwater testate amoebae species composition between the south-eastern part of Azerbaijan and other regions of Azerbaijan

A comparative analysis of freshwater testate amoebae species composition between the south-eastern part of Azerbaijan and other regions of Azerbaijan

Biodiversity, Distribution and Ecology of Testate Amoebae (Arcellinida and Euglyphida) from the Bulgarian Black Sea Coast and the related brackish lakes. A Synthesis

Abstract The studies on the marine and freshwater testate amoebae of the Bulgarian Black Sea littoral and some related coastal brackish lakes are briefly reviewed. So far, a total of 184 species and subspecies of testate amoebae from 18 families and 45 genera from orders of Arcellinida and Euglyphida were published in national and international journals. The underground waters of the Bulgarian marine sand supralittoral are better studied than the related continental lakes. A total of about 45 species of marine interstitial testate amoebae are known, so far, and a big part of them were for the first time described from the Black Sea littoral. It’s interesting to note the presence in the marine underground waters of the Black Sea littoral of many freshwater testate amoebae also, considered by us as eurybionts. That is due of the low and variable salinity of the littoral Black Sea waters during the year. The presence of some psammobiotic testate amoebae as Psammonobiotus lineare and Corythionella georgiana in some related brackish lakes is also of ecological interest. The general conclusion of the present synthesis is that the testate amoebae fauna of the Bulgarian Black Sea coast and the related with it many brackish and freshwater littoral lakes is few known yet and need more active researches.

Temperature transfer functions based on freshwater testate amoebae from China

Globally, lakes and reservoirs ecosystems are integral parts of ecological processes. Nevertheless, global warming is rapidly changing their function and sustainability, especially in the populated area of the northern hemisphere. Here we examined testate amoebae community and 10 environmental variables from 51 lakes and reservoirs across China and developed testate amoebae transfer functions for temperature based on both abundance- and biomass-datasets. A total of 169 testate amoebae taxa were identified. Our partial CCA analyses revealed that water temperature explained 5.15% (P = 0.006) and 5.57% (P = 0.008) of the total variance in testate amoebae abundance and biomass, respectively. The WA-PLS was the best model in abundance-based temperature transfer function (RMSEP = 2.87 °С, R2 = 0.60), whereas the MAT proved to be the best model for biomass-based temperature transfer function (RMSEP = 3.34 °С, R2 = 0.67). The application of all models should be carried out with suitable precautions. Our results suggested that freshwater testate amoebae could contribute to a better understanding of the ecological integrity and its vulnerability in inland aquatic environments.

Freshwater testate amoebae in the Belaya River basin (Northwestern Caucasus)

Fifty-two species and intraspecific taxa of testate amoebae have been detected in 24 different habitats in the Belaya River basin (Northwestern Caucasus). Four types of communities are distinguished which differ in the composition of the complex of dominating species: freshwater species from bottom sediments in water bodies and water courses, soil-dwelling species from inundated parts of floodplains, a mixture of soildwelling and freshwater species in different littoral biotopes, and eurybiontic species in moss hummocks along the banks.

Diversity and distribution of freshwater testate amoebae (protozoa) along latitudinal and trophic gradients in China.

Freshwater microbial diversity is subject to multiple stressors in the Anthropocene epoch. However, the effects of climate changes and human activities on freshwater protozoa remain poorly understood. In this study, the diversity and distribution of testate amoebae from the surface sediments were investigated in 51 Chinese lakes and reservoirs along two gradients, latitude and trophic status. A total of 169 taxa belonging to 24 genera were identified, and the most diverse and dominant genera were Difflugia (78 taxa), Centropyxis (26 taxa) and Arcella (12 taxa). Our analysis revealed that biomass of testate amoebae decreased significantly along the latitudinal gradient, while Shannon-Wiener indices and species richness presented an opposite trend (P < 0.05). The relationship of diversity and latitude is, we suspect, an artifact of the altitudinal distribution of our sites. Furthermore, biomass-based Shannon-Wiener index and species richness of testate amoebae were significantly unimodally related to trophic status (P < 0.05). This is the first large-scale study showing the effects of latitude and trophic status on diversity and distribution of testate amoebae in China. Therefore, our results provide valuable baseline data on testate amoebae and contribute to lake management and our understanding of the large-scale global patterns in microorganism diversity.Electronic supplementary materialThe online version of this article (doi:10.1007/s00248-014-0442-1) contains supplementary material, which is available to authorized users.

Linkages between Holocene paleoclimate and paleohydrogeology preserved in a Yucatan underwater cave

Three sediment cores spanning the last 4200 years from Aktun Ha Cave on the Yucatan Peninsula (Mexico) demonstrate that underwater caves can document changes to regional hydrogeology and climate. Benthic microfossils (testate amoebae, foraminifera), organic matter geochemistry (δ 13C, δ 15N, C/N), and particle size distributions were analyzed. However, microfossil paleoecology proved the most useful for indicating three salinity phases in the Aktun Ha sediment cores. Phase 1 (>4300 yr BP) contains predominantly foraminifera ( Physalidia simplex, 78%) that indicate the meteoric lens flooding the cave was initially brackish (salinity >3.5 g L −1). Phase 2 (2800–4300 Cal yr BP) has both freshwater testate amoebae ( Centropyxis spp. 40%) and P. simplex (42%), which indicates a slight freshening of the meteoric lens to 1.5–2 g L −1. Phase 3 (<2800 yr BP) is demarcated by an increase in testate amoebae abundance (90%) and diversity, including the colonization of Lagenodifflugia vas and Difflugia oblonga, with a reduction in P. simplex (10%). This last faunal shift represents the initiation of modern freshwater conditions in the cave (1.5 g L −1). This final freshening is synchronous with a significant reduction in the C/N ratio (e.g., Core 2: ∼27 to 19), which suggests an expansion of primary productivity in the adjacent cenote. The δ 15N values ranged from 1.5 to 3.5‰ with observed cycles likely from intervals of increased terrestrial OM input into the cave during high rainfall events (e.g., hurricanes). The observed paleoenvironmental shifts in the cave correlate well with regional precipitation patterns, aquifer recharge, and storm activity caused by southward migration of the Intertropical Convergence Zone. Therefore, regional climate change impacted eastern Yucatan groundwater during the mid to late Holocene. However, decelerating Holocene sea-level rise and aquifer occlusion are likely contributing factors. These results demonstrate that underwater cave sediments and microfossils can be useful proxies for aquifer evolution and climate change.

A preliminary study of the freshwater fauna of testate amoebae of southeast Azerbaijan

During 2005-2007, 75 species of the freshwater testate amoebae were found in the vicinities of Lenkoran (SE Azerbaijan). The morphology of 14 species is described. One genus and 3 species are new to science (Difflugia pisciformis sp.n., D. pseudoclaviformis sp.n., Lenkorania gen.n., Pseudodifflugia magna sp.n.). Eleven species are new for the fauna of the Caucasus and Azerbaijan.

Additional contribution to the study of the freshwater fauna of testate amoebae in southeast Azerbaijan

Investigations of the inland water bodies of southeast Azerbaijan (mainly near the city of Lenkoran and its suburbs) yielded 11 additional species of freshwater testate amoebae. Among these, 7 species (Oopyxis lenkoranica sp.n., Pentagonia azerbaijanica sp.n., Difflugia lenkoranica sp.n., D.talyshica sp.n., D.sapnakeranica sp.n., D.pressula sp.n., and D.girkanica sp.n.) are new to science. Descriptions of all 11 species are given.

Freshwater Testate Amoebae of Nine Yunnan Plateau Lakes, China

ABSTRACT The testate amoebae from nine major lakes in the Yunnan Plateau, southwest China were investigated from August to October 2003. Ninety-four species and subspecies belonging to 21 genera were found, and six species were new to the testate amoebae fauna of China. The most diverse genera were Dlfflugia (28 species), Centropyxis (22 species), Arcella (12 species), and Euglypha (seven species), while the predominant genera were Centropyxis (42.0%), Difflugia (21.4%), Arcella (9.7%), and Euglypha (8.2%). The most diverse testate amoebae fauna was found in a mesotrophic lake, Lake Yilong (57 species). The lowest species richness was recorded in the two hypereutrophic lakes, Lake Dianchi (7 species) and Lake Xingyun (11 species). The results suggest that the lake trophic status plays an important role in shaping community structure and in determining species diversity of testate amoebae.

Freshwater Testate Amoebae Communities from Île de la Possession, Crozet Archipelago, Subantarctica

An ecological study of the freshwater testate amoebae (Protozoa, Rhizopoda) on the subantarctic island Île de la Possession (Crozet Archipelago) revealed 85 taxa, belonging to 21 genera. Twenty-two taxa belonged to the genus Difflugia, typical for freshwater habitats whereas the genus Trinema showed the highest relative abundance. A cluster analysis revealed two communities: a Difflugiella crenulata assemblage and a Trinema lineare–T. enchelys assemblage. These communities, together with the results of a RDA analysis, represented a clear geographical separation on the island. The Difflugiella crenulata assemblage typified locations, with a high specific conductance and neutral to alkaline pH values, on the western part of the island. Aquatic habitats in the larger valleys on the eastern side of Île de la Possession, with a low conductivity and slightly acid pH values, were characterized by the Trinema assemblage. Weighted averaging and calibration were used to develop a statistical transfer function to infer the pH of freshwater bodies from the testate amoebae assemblages. The model is usable over a pH range of 5 to 9.

Microhabitat partitioning by freshwater testate amoebae (Protozoa: Rhizopoda) on Vallisneria gigantea leaves in an Australian billabong (ox-bow lake): preliminary results on community succession mechanisms on a micro-scale

Microhabitat partitioning by freshwater testate amoebae (Protozoa: Rhizopoda) on <i>Vallisneria gigantea</i> leaves in an Australian billabong (ox-bow lake): preliminary results on community succession mechanisms on a micro-scale

An Atlas of Freshwater Testate Amoebae.C. G. Ogden , R. H. Hedley

Previous articleNext article No AccessNew Biological BooksAn Atlas of Freshwater Testate Amoebae. C. G. Ogden , R. H. Hedley M. LevandowskyM. Levandowsky Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Quarterly Review of Biology Volume 55, Number 4Dec., 1980 Published in association with Stony Brook University Article DOIhttps://doi.org/10.1086/412025 Views: 1Total views on this site Copyright 1980 Stony Brook Foundation, Inc.PDF download Crossref reports no articles citing this article.

An Atlas of Freshwater Testate Amoebae

Using scanning electron micrographs, this book illustrates most of the common species of testate amoebae found in freshwater habitats. Information on the biology, ecology, geographical distribution, and classification is followed by descriptions of 95 species, each illustrated by several views of the shell. The text serves both as an identification guide and as an introduction to the biology and taxonomy of these freshwater protozoa. Readership: protozoologists, ecologists, limnologists, water tyreatment specialists, and micropaleontologists interested in recent sediments.

Ogden, C. G. &amp; Hedley, R. H. 1980. an Atlas of Freshwater Testate Amoebae. Oxford Univ. Press, 200 Madison Ave., New York Ny 10016. 222 Pp. $49.50.

The Journal of ProtozoologyVolume 27, Issue 3 p. 326-326 Ogden, C. G. & Hedley, R. H. 1980. an Atlas of Freshwater Testate Amoebae. Oxford Univ. Press, 200 Madison Ave., New York Ny 10016. 222 Pp. $49.50. NORMAN D. LEVINE, NORMAN D. LEVINE College of Veterinary Medicine, Univ. of Illinois, Urbana IL 61801.Search for more papers by this author NORMAN D. LEVINE, NORMAN D. LEVINE College of Veterinary Medicine, Univ. of Illinois, Urbana IL 61801.Search for more papers by this author First published: August 1980 https://doi.org/10.1111/j.1550-7408.1980.tb04269.xCitations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume27, Issue3August 1980Pages 326-326 RelatedInformation