Extensive morphological variability in asexually produced planktic foraminifera (original) (raw)
Related papers
2018
The size structure of plankton communities is an important determinant of their functions in marine ecosystems. However, few studies have quantified how organism size varies within species across space. Using a recently-digitised museum collection, we investigate at high intraspecific resolution how planktonic foraminifera, an important microfossil group, vary in size across the tropical and subtropical oceans of the world. We measured 3799 individuals of nine species in 53 seafloor sediments and analysed potential size biases in the museum collection. For each site, we obtained corresponding local values of mean annual sea-surface temperature (SST), net primary productivity (NPP), and relative abundance of each species. Given former studies, we expected species to reach largest shell sizes under optimal environmental conditions. At species level, we find the expected pattern; however, at population level, species greatly differ in how much size variation is explained by SST, NPP an...
The Journal of Foraminiferal Research, 1981
The environmental-morphologic relations in three species of living planktonic foraminifera have been studied in horizontal tows of known depths from an anchored station in the northeastern Pacific Ocean. The environmental and ecological information utilized includes in situ hydrographic, oxygen isotopic, and quantitative species-distribution data. The coiling direction of Globigerinita glutinata appears to be closely related to water temperature, suggesting that coiling ratios of this cosmopolitan species are a potentially useful paleoclimatic tool. Coiling direction in Globigerina bulloides is not related to water temperature, and shows no significant variation with water depth or test size. In Neogloboquadrina pachyderma, populations consisting of 100% sinistrally coiled specimens occur at a water temperature as high as 83°C. The positive correlation of maximum relative abundances with maximum test size in G. bulloides, G. glutinata, and N. pachyderma; and with the number of chambers in the final whorl in G. bulloides and N. pachyderma, supports the hypothesis, proposed by other authors, that optimum growth occurs in regions of optimum environment. The kummerform phenotype does not result from environmental stress. A morphometric-ecologic analysis of G. bulloides suggests that kummerform development is a consequence of an environmentally influenced genetic factor.
APPENDIX:Planktic foraminiferal diversity: logistic growth overprinted by a varying environment
Acta Biológica Colombiana, 2016
Cárdenas Rozo AL, Harries PJ. Planktic foraminiferal diversity: logistic growth overprinted by a varying environment. Acta biol. Colomb. 2016;21(3):501-508. The statistical analyses, were done using R (The R Project for Statistical Computing, www.r-project.org). This appendix includes: Supplementary data Supplementary methods Tables 1 to 11 Figures 1 to 4 Supplementary references
Observation of asexual reproduction with symbiont transmission in planktonic foraminifera
Journal of Plankton Research, 2020
Gamete release has been frequently observed in laboratory cultures of various species of planktonic foraminifera. Those observations have been taken as evidence that these organisms produce new generations exclusively by sexual reproduction. We report here the first observation of asexual reproduction in Globigerinita uvula, a small, microperforate foraminifera. The asexual phase was associated with the release of ca. 110 offspring, all of which hosted symbiotic algae that must have been passed on directly from the parent. This event was also the first observation of vertical transmission of symbionts in planktonic foraminifera. Although the trigger of the observed asexual reproduction and its frequency in nature remain unknown, our observation indicates that among the planktonic foraminifera, at least G. uvula has not abandoned the asexual phase of its life cycle.
Ontogenetic disparity in early planktic foraminifers
Journal of Micropalaeontology
Changes in morphology during ontogeny can have profound impacts on the physiology and biology of a species. Studies of ontogenetic disparity through time are rare because of the lack of preservation of developmental stages in the fossil record. As they grow by incremental chamber accretion and retain evidence of growth in their shell, planktic foraminifera are an ideal group for the study ontogenetic disparity through the evolution of a higher taxon. Here, we quantify different developmental stages in Jurassic foraminifers and infer the evolutionary implications of the shape of these earliest representatives of the group. Using a Zeiss Xradia micro-CT scanner, the development of Globuligerina bathoniana and Globuligerina oxfordiana from the Bathonian sediments of Gnaszyn, Poland, and Globuligerina balakhmatovae and Globuligerina tojeiraensis from the Kimmeridgian Tojeira Formation of Portugal was reconstructed. Disparity is low through the early evolution of planktic foraminifers. The number of chambers and range in surface area per unit volume are lower than in modern specimens. We interpret this morphology as an indication of opportunistic behaviour. The low morphological plasticity during the juvenile stage suggests that strong constraints on the juveniles, described in the modern ocean, were already acting on Jurassic specimens. The high surface area per unit volume in these developmental stages points towards the need to satisfy a higher metabolic demand than in the adult specimens. We are interpreting the lower chamber numbers as indicative of short life cycles and potentially rapid reproduction, both of which may have allowed these species to exploit the nutrient-rich waters of the Jurassic Tethys Ocean.
Predictability of intraspecific size variation in extant planktonic foraminifera
Planktonic foraminifera (PF) size varies greatly both among and within species. This variation affects our understanding of PF ecology and evolution as well as reconstructions of the ocean-climate system. It is currently accepted that PF species are largest under optimum environmental conditions, where abundance is maximised. This idea is based on observations from marine sediment assemblages; however, these observations either had limited intraspecific resolution or focused on a restricted part of each species' biogeographical range. Here we compile a new global PF shell size dataset to investigate the relationship between intraspecific size variation and abundance and sea surface temperature (SST). Our dataset contains 3817 individual size measurements on nine PF species in 53 surface sediments around the world. For each species, we fitted a generalised linear model of population shell size as function of local abundance (as an indicator of optimum environmental conditions) an...
Do Changes in Coiling Directions in Planktonic Foraminifera Correspond to Dimorphic Reproduction?
Oceanology, 2012
A total of 25 surface sediment samples, collected along a North South transect (from 9.69° N to 55.01° S and from 80° E and 40° E) in the south western Indian Ocean, were used to study the coiling direc tion patterns in foraminifera planktonic species Neogloboquadrina pachyderma, Globigerinita glutinata and Globigerina bulloides. Comparison between the coiling direction and mean proloculus size (MPS) revealed that all these profiles along N S transect were not in tandem and thus indicated non existence of any rela tionship between the coiling direction and reproductive modes expressed in terms of mean proloculus size.
Oceanographic controls on the diversity and extinction of planktonic foraminifera
Understanding the links between long-term biological evolution, the ocean-atmosphere system and plate tectonics is a central goal of Earth science. Although environmental perturbations of many different kinds are known to have affected long-term biological evolution, particularly during major mass extinction events 1,2 , the relative importance of physical environmental factors versus biological interactions in governing rates of extinction and origination through geological time remains unknown 2 . Here we use macrostratigraphic data from the Atlantic Ocean basin to show that changes in global species diversity and rates of extinction among planktonic foraminifera have been linked to tectonically and climatically forced changes in ocean circulation and chemistry from the Jurassic period to the present. Transient environmental perturbations, such as those that occurred after the asteroid impact at the end of the Cretaceous period 1 approximately 66 million years ago, and the Eocene/Oligocene greenhouse-icehouse transition 3,4 approximately 34 million years ago, are superimposed on this general long-term relationship. Rates of species origination, by contrast, are not correlated with corresponding macrostratigraphic quantities, indicating that physiochemical changes in the oceanatmosphere system affect evolution principally by driving the synchronous extinction of lineages that originated owing to more protracted and complex interactions between biological and environmental factors.
The FORCIS database: A global census of planktonic Foraminifera from ocean waters
Scientific Data
Planktonic Foraminifera are unique paleo-environmental indicators through their excellent fossil record in ocean sediments. Their distribution and diversity are affected by different environmental factors including anthropogenically forced ocean and climate change. Until now, historical changes in their distribution have not been fully assessed at the global scale. Here we present the FORCIS (Foraminifera Response to Climatic Stress) database on foraminiferal species diversity and distribution in the global ocean from 1910 until 2018 including published and unpublished data. The FORCIS database includes data collected using plankton tows, continuous plankton recorder, sediment traps and plankton pump, and contains ~22,000, ~157,000, ~9,000, ~400 subsamples, respectively (one single plankton aliquot collected within a depth range, time interval, size fraction range, at a single location) from each category. Our database provides a perspective of the distribution patterns of planktoni...