scholarly journals Does foraminiferal test size reflect changes in palaeoenvironmental conditions?—a case study from the southern Svalbard shelf

2020 ◽  
Vol 39 (0) ◽  
Author(s):  
Maciej M. Telesiński ◽  
Natalia Szymańska ◽  
Joanna Pawłowska ◽  
Marek Zajączkowski
2020 ◽  
Vol 35 (1) ◽  
Author(s):  
C. L. Todd ◽  
D. N. Schmidt ◽  
M. M. Robinson ◽  
S. De Schepper

2018 ◽  
Vol 18 ◽  
pp. 775-781 ◽  
Author(s):  
Marilén Fernández ◽  
Nora I. Maidana ◽  
J. Federico Ponce ◽  
Jimena Oría ◽  
Mónica Salemme ◽  
...  

2020 ◽  
Vol 50 (4) ◽  
pp. 319-329
Author(s):  
Meng Li ◽  
Yanli Lei ◽  
Tiegang Li ◽  
Shuaishuai Dong

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.


Geobios ◽  
2007 ◽  
Vol 40 (3) ◽  
pp. 251-265 ◽  
Author(s):  
Hara Drinia ◽  
Assimina Antonarakou ◽  
Nikolaos Tsaparas ◽  
George Kontakiotis

Paleobiology ◽  
2016 ◽  
Vol 42 (4) ◽  
pp. 595-611 ◽  
Author(s):  
Caitlin R. Keating-Bitonti ◽  
Jonathan L. Payne

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.


2020 ◽  
Vol 6 (3) ◽  
pp. 316-354
Author(s):  
Armin Salsani ◽  
◽  
Abdolhossein Amini ◽  
Shahram shariati ◽  
Seyed Ali Aghanabati ◽  
...  

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