Calibration of the repeatability of foraminiferal test size and shape measures with recommendations for future use

Abstract This study explored the response to salinity of intertidal foraminiferal assemblages from the Yellow Sea by culturing them for 100 days at six constant salinity levels (17, 22, 27, 32, 37, and 42 psu) in laboratory microcosms with four replicates each. A total of 7,471 live (stained) foraminiferal specimens were obtained and analyzed. The diversity parameters of foraminiferal assemblages (species richness, Margalef index, Shannon-Wiener index, and Fisher's alpha) declined significantly when the salinity was increased or decreased from the field value, but foraminiferal abundance was highly resistant to salinity. In addition, salinity exerted different effects on foraminifera from different orders. Specifically, the proportion of species from Order Miliolida significantly increased whereas that of species from Order Rotaliida decreased with increasing salinity. High salinity-tolerant species Ammonia aomoriensis, Cribrononion gnythosuturatum, Ammonia tepida, and Quinqueloculina seminula could fill unoccupied ecological niches when the proportion of salinity-sensitive species has declined. Furthermore, our morphometric results showed that foraminiferal test size was significantly negatively correlated with salinity, and numerous abnormal specimens appeared in foraminiferal assemblages when salinity deviated from the field value. Our study revealed that intertidal foraminiferal assemblages had high adaptability at different salinities because of the existence of high salinity-tolerant dominant species. In addition, salinity variation can significantly alter foraminiferal morphology in test size and abnormality.

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

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2020.568904 ◽

2020 ◽

Vol 8 ◽

Author(s):

Andrew L. Macumber ◽

Helen M. Roe ◽

Stephen V. Prentice ◽

Carl D. Sayer ◽

Helen Bennion ◽

...

Keyword(s):

Community Dynamics ◽

Testate Amoebae ◽

Community Change ◽

Testate Amoeba ◽

Geometric Morphometric ◽

Test Size ◽

Size And Shape ◽

Loch Leven ◽

Macrophyte Community ◽

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.

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TAXONOMIC CONSIDERATION AND STRATIGRAPHIC IMPLICATION OF THE ACCELERATED EVOLUTION OF THE MAASTRICHTIAN-EOCENE TRANSITION OF TWENTY BENTHIC FORAMINIFERAL SPECIES IN THE TETHYS

Earth Sciences Pakistan ◽

10.26480/esp.01.2020.01.06 ◽

2020 ◽

Vol 4 (1) ◽

pp. 01-06

Author(s):

Haidar Salim Anan

Keyword(s):

Size And Shape ◽

Foraminiferal Species ◽

Accelerated Evolution ◽

Taxonomic Consideration ◽

Foraminiferal Test

Within the Maastrichtian-Eocene transition in some localities in the Tethys, ten trends of accelerated evolution are recognized within twenty species belong to eight benthic foraminiferal genera: Siphogaudryina, Textularia, Pseudoclavulina, Pyramidulina, Frondicularia, Hopkinsina, Gyroidinoides and Angulogavelinella. Three out of the identified species are treated here to be new: Textularia haquei, Pyramidulina leroyi and Hopkinsina haquei. These lineages marked by changes in the morphology of the foraminiferal test, throughout the number, size and shape of chambers, ornamentation, size and position of aperture, suture and umbilicus. The identified Maastrichtian-Eocene species in this study are recognized in different localities in the Tethys: USA, France, Italy, Tunisia, Egypt, Jordan, UAE, Qatar and Pakistan.

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Anomalous shifts in tropical Pacific planktonic and benthic foraminiferal test size during the Paleocene–Eocene thermal maximum

Palaeogeography Palaeoclimatology Palaeoecology ◽

10.1016/j.palaeo.2005.12.017 ◽

2006 ◽

Vol 237 (2-4) ◽

pp. 456-464 ◽

Cited By ~ 48

Author(s):

Kunio Kaiho ◽

Kotaro Takeda ◽

Maria Rose Petrizzo ◽

James C. Zachos

Keyword(s):

Tropical Pacific ◽

Test Size ◽

Thermal Maximum ◽

Foraminiferal Test

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Physicochemical controls on biogeographic variation of benthic foraminiferal test size and shape

Paleobiology ◽

10.1017/pab.2016.7 ◽

2016 ◽

Vol 42 (4) ◽

pp. 595-611 ◽

Cited By ~ 5

Author(s):

Caitlin R. Keating-Bitonti ◽

Jonathan L. Payne

Keyword(s):

Surface Area ◽

Continental Margin ◽

Water Depth ◽

Benthic Foraminifera ◽

Area Ratio ◽

Surface Area Ratio ◽

Test Volume ◽

Test Size ◽

The North ◽

Foraminiferal Test

AbstractThe sizes and shapes of marine organisms often vary systematically across latitude and water depth, but the environmental factors that mediate these gradients in morphology remain incompletely understood. A key challenge is isolating the individual contributions of many, often correlated, environmental variables of potential biological significance. Benthic foraminifera, a diverse group of rhizarian protists that inhabit nearly all marine environments, provide an unparalleled opportunity to test statistically among the various potential controls on size and volume–to–surface area ratio. Here, we use 7035 occurrences of 541 species of Rotallid foraminifera across 946 localities spanning more than 60 degrees of latitude and 1600 m of water depth around the North American continental margin to assess the relative influences of temperature, oxygen availability, carbonate saturation, and particulate organic carbon flux on their test volume and volume–to–surface area ratio. For the North American data set as a whole, the best model includes temperature and dissolved oxygen concentration as predictors. This model also applies to data from the Pacific continental margin in isolation, but only temperature is included in the best model for the Atlantic. Because these findings are consistent with predictions from the first principles of cell physiology, we interpret these statistical associations as the expressions of physiological selective pressures on test size and shape from the physical environment. Regarding existing records of temporal variation in foraminiferal test size across geological time in light of these findings suggests that the importance of temperature variation on the evolution of test volume and volume–to–surface area ratio may be underappreciated. In particular, warming may have played as important a role as reduced oxygen availability in causing test size reduction during past episodes of environmental crisis and is expected to inflict metabolic stress on benthic foraminifera over the next century due to anthropogenic climate change.

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Size variations in foraminifers from the early Permian to the Late Triassic: implications for the Guadalupian–Lopingian and the Permian–Triassic mass extinctions

Paleobiology ◽

10.1017/pab.2020.37 ◽

2020 ◽

Vol 46 (4) ◽

pp. 511-532

Author(s):

Yan Feng ◽

Haijun Song ◽

David P. G. Bond

Keyword(s):

Morphological Characteristics ◽

Late Triassic ◽

Mass Extinctions ◽

Triassic Boundary ◽

Test Size ◽

Global Database ◽

Catastrophic Loss ◽

Extinction Events ◽

Permian Triassic Boundary ◽

Foraminiferal Test

AbstractThe final 10 Myr of the Paleozoic saw two of the biggest biological crises in Earth history: the middlePermian extinction (often termed the Guadalupian–Lopingian extinction [GLE]) that was followed 7–8 Myr later by Earth's most catastrophic loss of diversity, the Permian–Triassic mass extinction (PTME). These crises are not only manifest as sharp decreases in biodiversity and—particularly for the PTME—total ecosystem collapse, but they also drove major changes in biological morphological characteristics such as the Lilliput effect. The evolution of test size among different clades of foraminifera during these two extinction events has been less studied. We analyzed a global database of foraminiferal test size (volume) including 20,226 specimens in 464 genera, 98 families, and 9 suborders from 632 publications. Our analyses reveal significant reductions in foraminiferal mean test size across the Guadalupian/Lopingian boundary (GLB) and the Permian/Triassic boundary (PTB), from 8.89 to 7.60 log10 μm3 (lg μm3) and from 7.25 to 5.82 lg μm3, respectively. The decline in test size across the GLB is a function of preferential extinction of genera exhibiting gigantism such as fusulinoidean fusulinids. Other clades show little change in size across the GLB. In contrast, all Lopingian suborders in our analysis (Fusulinina, Lagenina, Miliolina, and Textulariina) experienced a significant decrease in test size across the PTB, mainly due to size-biased extinction and within-lineage change. The PTME was clearly a major catastrophe that affected many groups simultaneously, and the GLE was more selective, perhaps hinting at a subtler, less extreme driver than the later PTME.

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